On Tue, 7 Aug 2012, Konrad Rzeszutek Wilk wrote:

On Mon, Aug 06, 2012 at 03:27:04PM +0100, Stefano Stabellini wrote:

...

• Basic hypervisor.h and interface.h definitions.
• Skeleton enlighten.c, set xen_start_info to an empty struct.
• Make xen_initial_domain dependent on the SIF_PRIVILIGED_BIT.

The new code only compiles when CONFIG_XEN is set, that is going to be added to arch/arm/Kconfig in patch #11 "xen/arm: introduce CONFIG_XEN on ARM".

You can add my Ack, but do one change pls:

Thanks! I'll make the changes.

...

+/* XXX: Move pvclock definitions some place arch independent */

Just use 'TODO'

...

+struct pvclock_vcpu_time_info {

• u32 version;
• u32 pad0;
• u64 tsc_timestamp;
• u64 system_time;
• u32 tsc_to_system_mul;
• s8 tsc_shift;
• u8 flags;
• u8 pad[2];

+} __attribute__((__packed__)); /* 32 bytes */

+struct pvclock_wall_clock {

• u32 version;
• u32 sec;
• u32 nsec;

+} __attribute__((__packed__));

Mention the size and why it is OK to have it be a weird size while the one above is nicely padded.

...

+#endif

+#endif /* _ASM_ARM_XEN_INTERFACE_H */ diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile new file mode 100644 index 0000000..0bad594 --- /dev/null +++ b/arch/arm/xen/Makefile @@ -0,0 +1 @@ +obj-y := enlighten.o diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c new file mode 100644 index 0000000..d27c2a6 --- /dev/null +++ b/arch/arm/xen/enlighten.c @@ -0,0 +1,35 @@ +#include <xen/xen.h> +#include <xen/interface/xen.h> +#include <xen/interface/memory.h> +#include <xen/platform_pci.h> +#include <asm/xen/hypervisor.h> +#include <asm/xen/hypercall.h> +#include <linux/module.h>

+struct start_info _xen_start_info; +struct start_info *xen_start_info = &_xen_start_info; +EXPORT_SYMBOL_GPL(xen_start_info);

+enum xen_domain_type xen_domain_type = XEN_NATIVE; +EXPORT_SYMBOL_GPL(xen_domain_type);

+struct shared_info xen_dummy_shared_info; +struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;

+DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);

+/* XXX: to be removed */

s/XXX/TODO/ here, and mention pls why it needs to be removed.

...

+__read_mostly int xen_have_vector_callback; +EXPORT_SYMBOL_GPL(xen_have_vector_callback);

+int xen_platform_pci_unplug = XEN_UNPLUG_ALL; +EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);

On Mon, Aug 06, 2012 at 03:27:05PM +0100, Stefano Stabellini wrote:

Use r12 to pass the hypercall number to the hypervisor.

We need a register to pass the hypercall number because we might not know it at compile time and HVC only takes an immediate argument.

Among the available registers r12 seems to be the best choice because it is defined as "intra-procedure call scratch register".

Use the ISS to pass an hypervisor specific tag.

Changes in v2:

• define an HYPERCALL macro for 5 arguments hypercall wrappers, even if

at the moment is unused;

• use ldm instead of pop;
• fix up comments.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

arch/arm/include/asm/xen/hypercall.h | 50 ++++++++++++++++ arch/arm/xen/Makefile | 2 +- arch/arm/xen/hypercall.S | 106 ++++++++++++++++++++++++++++++++++ 3 files changed, 157 insertions(+), 1 deletions(-) create mode 100644 arch/arm/include/asm/xen/hypercall.h create mode 100644 arch/arm/xen/hypercall.S

[...]

diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S new file mode 100644 index 0000000..074f5ed --- /dev/null +++ b/arch/arm/xen/hypercall.S @@ -0,0 +1,106 @@ +/******************************************************************************

• • hypercall.S
• • Xen hypercall wrappers
• • Stefano Stabellini stefano.stabellini@eu.citrix.com, Citrix, 2012
• • This program is free software; you can redistribute it and/or
• • modify it under the terms of the GNU General Public License version 2
• • as published by the Free Software Foundation; or, when distributed
• • separately from the Linux kernel or incorporated into other
• • software packages, subject to the following license:
• • Permission is hereby granted, free of charge, to any person obtaining a copy
• • of this source file (the "Software"), to deal in the Software without
• • restriction, including without limitation the rights to use, copy, modify,
• • merge, publish, distribute, sublicense, and/or sell copies of the Software,
• • and to permit persons to whom the Software is furnished to do so, subject to
• • the following conditions:
• • The above copyright notice and this permission notice shall be included in
• • all copies or substantial portions of the Software.
• • THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
• • IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
• • FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
• • AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
• • LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
• • FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
• • IN THE SOFTWARE.
• */

+/*

• • The Xen hypercall calling convention is very similar to the ARM
• • procedure calling convention: the first paramter is passed in r0, the
• • second in r1, the third in r2 and the fourth in r3. Considering that
• • Xen hypercalls have 5 arguments at most, the fifth paramter is passed
• • in r4, differently from the procedure calling convention of using the
• • stack for that case.
• • The hypercall number is passed in r12.
• • The return value is in r0.
• • The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
• • hypercall tag.
• */

+#include <linux/linkage.h> +#include <asm/assembler.h> +#include <xen/interface/xen.h>

+/* HVC 0xEA1 */ +#ifdef CONFIG_THUMB2_KERNEL +#define xen_hvc .word 0xf7e08ea1 +#else +#define xen_hvc .word 0xe140ea71 +#endif

Consider using my opcode injection helpers patch for this (see separate repost: [PATCH v2 REPOST 0/4] ARM: opcodes: Facilitate custom opcode injection), assuming that nobody objects to it. This should mean that the right opcodes get generated when building a kernel for a big- endian target for example.

I believe the __HVC(imm) macro which I put in <asm/opcodes-virt.h> as an example should do what you need in this case.

+#define HYPERCALL_SIMPLE(hypercall) \ +ENTRY(HYPERVISOR_##hypercall) \

• mov r12, #__HYPERVISOR_##hypercall; \
• xen_hvc; \
• mov pc, lr; \

+ENDPROC(HYPERVISOR_##hypercall)

+#define HYPERCALL0 HYPERCALL_SIMPLE +#define HYPERCALL1 HYPERCALL_SIMPLE +#define HYPERCALL2 HYPERCALL_SIMPLE +#define HYPERCALL3 HYPERCALL_SIMPLE +#define HYPERCALL4 HYPERCALL_SIMPLE

+#define HYPERCALL5(hypercall) \ +ENTRY(HYPERVISOR_##hypercall) \

• stmdb sp!, {r4} \
• ldr r4, [sp, #4] \
• mov r12, #__HYPERVISOR_##hypercall; \
• xen_hvc \
• ldm sp!, {r4} \
• mov pc, lr \

+ENDPROC(HYPERVISOR_##hypercall)

•            .text
  

+HYPERCALL2(xen_version); +HYPERCALL3(console_io); +HYPERCALL3(grant_table_op); +HYPERCALL2(sched_op); +HYPERCALL2(event_channel_op); +HYPERCALL2(hvm_op); +HYPERCALL2(memory_op); +HYPERCALL2(physdev_op);

+ENTRY(privcmd_call)

• stmdb sp!, {r4}
• mov r12, r0
• mov r0, r1
• mov r1, r2
• mov r2, r3
• ldr r3, [sp, #8]
• ldr r4, [sp, #4]
• xen_hvc
• ldm sp!, {r4}
• mov pc, lr

Note that the preferred entry/exit sequences in such cases are:

stmfd sp!, {r4,lr} ... ldmfd sp!, {r4,pc}

...but it works either way. I would bother to change it unless you have other changes to make too.

Cheers ---Dave

On Thu, Aug 09, 2012 at 04:37:24PM +0100, Stefano Stabellini wrote:

On Wed, 8 Aug 2012, Dave Martin wrote:

...

On Mon, Aug 06, 2012 at 03:27:05PM +0100, Stefano Stabellini wrote:

...

Use r12 to pass the hypercall number to the hypervisor.

We need a register to pass the hypercall number because we might not know it at compile time and HVC only takes an immediate argument.

Among the available registers r12 seems to be the best choice because it is defined as "intra-procedure call scratch register".

Use the ISS to pass an hypervisor specific tag.

Changes in v2:

• define an HYPERCALL macro for 5 arguments hypercall wrappers, even if

at the moment is unused;

• use ldm instead of pop;
• fix up comments.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

arch/arm/include/asm/xen/hypercall.h | 50 ++++++++++++++++ arch/arm/xen/Makefile | 2 +- arch/arm/xen/hypercall.S | 106 ++++++++++++++++++++++++++++++++++ 3 files changed, 157 insertions(+), 1 deletions(-) create mode 100644 arch/arm/include/asm/xen/hypercall.h create mode 100644 arch/arm/xen/hypercall.S

[...]

...

diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S new file mode 100644 index 0000000..074f5ed --- /dev/null +++ b/arch/arm/xen/hypercall.S @@ -0,0 +1,106 @@ +/******************************************************************************

• • hypercall.S
• • Xen hypercall wrappers
• • Stefano Stabellini stefano.stabellini@eu.citrix.com, Citrix, 2012
• • This program is free software; you can redistribute it and/or
• • modify it under the terms of the GNU General Public License version 2
• • as published by the Free Software Foundation; or, when distributed
• • separately from the Linux kernel or incorporated into other
• • software packages, subject to the following license:
• • Permission is hereby granted, free of charge, to any person obtaining a copy
• • of this source file (the "Software"), to deal in the Software without
• • restriction, including without limitation the rights to use, copy, modify,
• • merge, publish, distribute, sublicense, and/or sell copies of the Software,
• • and to permit persons to whom the Software is furnished to do so, subject to
• • the following conditions:
• • The above copyright notice and this permission notice shall be included in
• • all copies or substantial portions of the Software.
• • THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
• • IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
• • FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
• • AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
• • LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
• • FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
• • IN THE SOFTWARE.
• */

+/*

• • The Xen hypercall calling convention is very similar to the ARM
• • procedure calling convention: the first paramter is passed in r0, the
• • second in r1, the third in r2 and the fourth in r3. Considering that
• • Xen hypercalls have 5 arguments at most, the fifth paramter is passed
• • in r4, differently from the procedure calling convention of using the
• • stack for that case.
• • The hypercall number is passed in r12.
• • The return value is in r0.
• • The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
• • hypercall tag.
• */

+#include <linux/linkage.h> +#include <asm/assembler.h> +#include <xen/interface/xen.h>

+/* HVC 0xEA1 */ +#ifdef CONFIG_THUMB2_KERNEL +#define xen_hvc .word 0xf7e08ea1 +#else +#define xen_hvc .word 0xe140ea71 +#endif

Consider using my opcode injection helpers patch for this (see separate repost: [PATCH v2 REPOST 0/4] ARM: opcodes: Facilitate custom opcode injection), assuming that nobody objects to it. This should mean that the right opcodes get generated when building a kernel for a big- endian target for example.

I believe the __HVC(imm) macro which I put in <asm/opcodes-virt.h> as an example should do what you need in this case.

Sure I can do that. Maybe I'll add another patch at the end of my series to replace xen_hvc with __HVC(0xEA1), so that it remains independent from your series. I have learned through experience that avoiding cross patch series dependencies help to reduce the amount of headaches during merge windows :)

I agree. I'll let you know when my patch gets merged -- in the meantime, it makes sense for you to keep your existing code.

...

...

+#define HYPERCALL_SIMPLE(hypercall) \ +ENTRY(HYPERVISOR_##hypercall) \

• mov r12, #__HYPERVISOR_##hypercall; \
• xen_hvc; \
• mov pc, lr; \

+ENDPROC(HYPERVISOR_##hypercall)

+#define HYPERCALL0 HYPERCALL_SIMPLE +#define HYPERCALL1 HYPERCALL_SIMPLE +#define HYPERCALL2 HYPERCALL_SIMPLE +#define HYPERCALL3 HYPERCALL_SIMPLE +#define HYPERCALL4 HYPERCALL_SIMPLE

+#define HYPERCALL5(hypercall) \ +ENTRY(HYPERVISOR_##hypercall) \

• stmdb sp!, {r4} \
• ldr r4, [sp, #4] \
• mov r12, #__HYPERVISOR_##hypercall; \
• xen_hvc \
• ldm sp!, {r4} \
• mov pc, lr \

+ENDPROC(HYPERVISOR_##hypercall)

•            .text
  

+HYPERCALL2(xen_version); +HYPERCALL3(console_io); +HYPERCALL3(grant_table_op); +HYPERCALL2(sched_op); +HYPERCALL2(event_channel_op); +HYPERCALL2(hvm_op); +HYPERCALL2(memory_op); +HYPERCALL2(physdev_op);

+ENTRY(privcmd_call)

• stmdb sp!, {r4}
• mov r12, r0
• mov r0, r1
• mov r1, r2
• mov r2, r3
• ldr r3, [sp, #8]
• ldr r4, [sp, #4]
• xen_hvc
• ldm sp!, {r4}
• mov pc, lr

Note that the preferred entry/exit sequences in such cases are:

stmfd sp!, {r4,lr} ... ldmfd sp!, {r4,pc}

...but it works either way. I would bother to change it unless you have other changes to make too.

Wouldn't this needlessly save and restore one more register (lr) to the stack? I would try to keep the hypercall wrappers as small as possible...

Argh, ignore me -- I was hallucinating for some reason that we actually needed to save lr, but we don't.

Using the stmfd/ldmfd mnemonics might still be nicer than stmdb/ldm, since the fd suffix makes the stack semantics more obvious, and the code looks more symmetrical. This was the conventional way to write these mnemonics before the "push" and "pop" mnemonics existed.

That's purely cosmetic, though.

Cheers ---Dave

On Tue, 7 Aug 2012, Konrad Rzeszutek Wilk wrote:

On Mon, Aug 06, 2012 at 03:27:09PM +0100, Stefano Stabellini wrote:

...

Changes in v2:

• remove pvclock hack;
• remove include linux/types.h from xen/interface/xen.h.

I think I can take in my tree now right by itself right? Or do you want to keep this in your patchqueue? If so, Ack from me.

Yep, just go ahead and take the patch, thanks.

...

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

arch/x86/include/asm/xen/interface.h | 2 ++ drivers/tty/hvc/hvc_xen.c | 2 ++ drivers/xen/grant-table.c | 1 + drivers/xen/xenbus/xenbus_probe_frontend.c | 1 + include/xen/interface/xen.h | 1 - include/xen/privcmd.h | 1 + 6 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/xen/interface.h b/arch/x86/include/asm/xen/interface.h index cbf0c9d..a93db16 100644 --- a/arch/x86/include/asm/xen/interface.h +++ b/arch/x86/include/asm/xen/interface.h @@ -121,6 +121,8 @@ struct arch_shared_info { #include "interface_64.h" #endif +#include <asm/pvclock-abi.h>

#ifndef __ASSEMBLY__ /*

• The following is all CPU context. Note that the fpu_ctxt block is filled

diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c index 944eaeb..dc07f56 100644 --- a/drivers/tty/hvc/hvc_xen.c +++ b/drivers/tty/hvc/hvc_xen.c @@ -21,6 +21,7 @@ #include <linux/console.h> #include <linux/delay.h> #include <linux/err.h> +#include <linux/irq.h> #include <linux/init.h> #include <linux/types.h> #include <linux/list.h> @@ -35,6 +36,7 @@ #include <xen/page.h> #include <xen/events.h> #include <xen/interface/io/console.h> +#include <xen/interface/sched.h> #include <xen/hvc-console.h> #include <xen/xenbus.h> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 0bfc1ef..1d0d95e 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -47,6 +47,7 @@ #include <xen/interface/memory.h> #include <xen/hvc-console.h> #include <asm/xen/hypercall.h> +#include <asm/xen/interface.h> #include <asm/pgtable.h> #include <asm/sync_bitops.h> diff --git a/drivers/xen/xenbus/xenbus_probe_frontend.c b/drivers/xen/xenbus/xenbus_probe_frontend.c index a31b54d..3159a37 100644 --- a/drivers/xen/xenbus/xenbus_probe_frontend.c +++ b/drivers/xen/xenbus/xenbus_probe_frontend.c @@ -21,6 +21,7 @@ #include <xen/xenbus.h> #include <xen/events.h> #include <xen/page.h> +#include <xen/xen.h> #include <xen/platform_pci.h> diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h index a890804..3871e47 100644 --- a/include/xen/interface/xen.h +++ b/include/xen/interface/xen.h @@ -10,7 +10,6 @@ #define __XEN_PUBLIC_XEN_H__ #include <asm/xen/interface.h> -#include <asm/pvclock-abi.h> /*

• XEN "SYSTEM CALLS" (a.k.a. HYPERCALLS).

diff --git a/include/xen/privcmd.h b/include/xen/privcmd.h index 17857fb..4d58881 100644 --- a/include/xen/privcmd.h +++ b/include/xen/privcmd.h @@ -35,6 +35,7 @@ #include <linux/types.h> #include <linux/compiler.h> +#include <xen/interface/xen.h> typedef unsigned long xen_pfn_t; -- 1.7.2.5

On 06/08/12 15:27, Stefano Stabellini wrote:

Check for a "/xen" node in the device tree, if it is present set xen_domain_type to XEN_HVM_DOMAIN and continue initialization.

Map the real shared info page using XENMEM_add_to_physmap with XENMAPSPACE_shared_info.

Changes in v2:

• replace pr_info with pr_debug.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

arch/arm/xen/enlighten.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 52 insertions(+), 0 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index d27c2a6..102d823 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -5,6 +5,9 @@ #include <asm/xen/hypervisor.h> #include <asm/xen/hypercall.h> #include <linux/module.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/of_address.h> struct start_info _xen_start_info; struct start_info *xen_start_info = &_xen_start_info; @@ -33,3 +36,52 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma, return -ENOSYS; } EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);

+/*

• • == Xen Device Tree format ==
• • • /xen node;
• • • compatible "arm,xen";
• • • one interrupt for Xen event notifications;
• • • one memory region to map the grant_table.
• */

These needs to be documented in Documentation/devicetree/bindings/ and should be sent to the devicetree-discuss mailing list for review.

The node should be called 'hypervisor' I think.

The first word of the compatible string is the vendor/organization that defined the binding so should be "xen" here. This does give a odd looking "xen,xen" but we'll have to live with that.

I'd suggest that the DT provided by the hypervisor or tools give the hypercall ABI version in the compatible string as well. e.g.,

hypervisor { compatible = "xen,xen-4.3", "xen,xen" };

I missed the Xen patch that adds this node for dom0. Can you point me to it?

David

+static int __init xen_guest_init(void) +{

• struct xen_add_to_physmap xatp;
• static struct shared_info *shared_info_page = 0;
• struct device_node *node;
• node = of_find_compatible_node(NULL, NULL, "arm,xen");
• if (!node) {

• pr_debug("No Xen support\n");
  

• return 0;
  

• }
• xen_domain_type = XEN_HVM_DOMAIN;
• if (!shared_info_page)

• shared_info_page = (struct shared_info *)
  

• 	get_zeroed_page(GFP_KERNEL);
  

• if (!shared_info_page) {

• pr_err("not enough memory\n");
  

• return -ENOMEM;
  

• }
• xatp.domid = DOMID_SELF;
• xatp.idx = 0;
• xatp.space = XENMAPSPACE_shared_info;
• xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
• if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))

• BUG();
  

• HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
• /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info

• * page, we use it in the event channel upcall and in some pvclock
  

• * related functions. We don't need the vcpu_info placement
  

• * optimizations because we don't use any pv_mmu or pv_irq op on
  

• * HVM.
  

• * The shared info contains exactly 1 CPU (the boot CPU). The guest
  

• * is required to use VCPUOP_register_vcpu_info to place vcpu info
  

• * for secondary CPUs as they are brought up. */
  

• per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
• return 0;

+} +core_initcall(xen_guest_init);

On Mon, Aug 06, 2012 at 03:27:10PM +0100, Stefano Stabellini wrote:

Check for a "/xen" node in the device tree, if it is present set xen_domain_type to XEN_HVM_DOMAIN and continue initialization.

Map the real shared info page using XENMEM_add_to_physmap with XENMAPSPACE_shared_info.

Changes in v2:

• replace pr_info with pr_debug.

I second what David mentioned. The other thing is that you are going to need to rebase this on top of v3.5-rc1, as Olaf's patches have changed the shared_info_page a bit.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

arch/arm/xen/enlighten.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 52 insertions(+), 0 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index d27c2a6..102d823 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -5,6 +5,9 @@ #include <asm/xen/hypervisor.h> #include <asm/xen/hypercall.h> #include <linux/module.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/of_address.h> struct start_info _xen_start_info; struct start_info *xen_start_info = &_xen_start_info; @@ -33,3 +36,52 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma, return -ENOSYS; } EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);

+/*

• • == Xen Device Tree format ==
• • • /xen node;
• • • compatible "arm,xen";
• • • one interrupt for Xen event notifications;
• • • one memory region to map the grant_table.
• */

+static int __init xen_guest_init(void) +{

• struct xen_add_to_physmap xatp;
• static struct shared_info *shared_info_page = 0;
• struct device_node *node;
• node = of_find_compatible_node(NULL, NULL, "arm,xen");
• if (!node) {

• pr_debug("No Xen support\n");
  

• return 0;
  

• }
• xen_domain_type = XEN_HVM_DOMAIN;
• if (!shared_info_page)

• shared_info_page = (struct shared_info *)
  

• 	get_zeroed_page(GFP_KERNEL);
  

• if (!shared_info_page) {

• pr_err("not enough memory\n");
  

• return -ENOMEM;
  

• }
• xatp.domid = DOMID_SELF;
• xatp.idx = 0;
• xatp.space = XENMAPSPACE_shared_info;
• xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
• if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))

• BUG();
  

• HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
• /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info

• * page, we use it in the event channel upcall and in some pvclock
  

• * related functions. We don't need the vcpu_info placement
  

• * optimizations because we don't use any pv_mmu or pv_irq op on
  

• * HVM.
  

• * The shared info contains exactly 1 CPU (the boot CPU). The guest
  

• * is required to use VCPUOP_register_vcpu_info to place vcpu info
  

• * for secondary CPUs as they are brought up. */
  

• per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
• return 0;

+}

+core_initcall(xen_guest_init);

1.7.2.5

On Mon, Aug 06, 2012 at 03:27:11PM +0100, Stefano Stabellini wrote:

All the original Xen headers have xen_pfn_t as mfn and pfn type, however when they have been imported in Linux, xen_pfn_t has been replaced with unsigned long. That might work for x86 and ia64 but it does not for arm. Bring back xen_pfn_t and let each architecture define xen_pfn_t as they see fit.

Ack.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

arch/arm/include/asm/xen/interface.h | 4 ++++ arch/ia64/include/asm/xen/interface.h | 5 ++++- arch/x86/include/asm/xen/interface.h | 5 +++++ include/xen/interface/grant_table.h | 4 ++-- include/xen/interface/memory.h | 6 +++--- include/xen/interface/platform.h | 4 ++-- include/xen/interface/xen.h | 6 +++--- include/xen/privcmd.h | 2 -- 8 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/arch/arm/include/asm/xen/interface.h b/arch/arm/include/asm/xen/interface.h index ab99270..f904dcc 100644 --- a/arch/arm/include/asm/xen/interface.h +++ b/arch/arm/include/asm/xen/interface.h @@ -25,6 +25,9 @@ } while (0) #ifndef __ASSEMBLY__ +/* Explicitly size integers that represent pfns in the interface with

• • Xen so that we can have one ABI that works for 32 and 64 bit guests. */

+typedef uint64_t xen_pfn_t; /* Guest handles for primitive C types. */ __DEFINE_GUEST_HANDLE(uchar, unsigned char); __DEFINE_GUEST_HANDLE(uint, unsigned int); @@ -35,6 +38,7 @@ DEFINE_GUEST_HANDLE(long); DEFINE_GUEST_HANDLE(void); DEFINE_GUEST_HANDLE(uint64_t); DEFINE_GUEST_HANDLE(uint32_t); +DEFINE_GUEST_HANDLE(xen_pfn_t); /* Maximum number of virtual CPUs in multi-processor guests. */ #define MAX_VIRT_CPUS 1 diff --git a/arch/ia64/include/asm/xen/interface.h b/arch/ia64/include/asm/xen/interface.h index 09d5f7f..686464e 100644 --- a/arch/ia64/include/asm/xen/interface.h +++ b/arch/ia64/include/asm/xen/interface.h @@ -67,6 +67,10 @@ #define set_xen_guest_handle(hnd, val) do { (hnd).p = val; } while (0) #ifndef __ASSEMBLY__ +/* Explicitly size integers that represent pfns in the public interface

• • with Xen so that we could have one ABI that works for 32 and 64 bit
• • guests. */

+typedef unsigned long xen_pfn_t; /* Guest handles for primitive C types. */ __DEFINE_GUEST_HANDLE(uchar, unsigned char); __DEFINE_GUEST_HANDLE(uint, unsigned int); @@ -79,7 +83,6 @@ DEFINE_GUEST_HANDLE(void); DEFINE_GUEST_HANDLE(uint64_t); DEFINE_GUEST_HANDLE(uint32_t); -typedef unsigned long xen_pfn_t; DEFINE_GUEST_HANDLE(xen_pfn_t); #define PRI_xen_pfn "lx" #endif diff --git a/arch/x86/include/asm/xen/interface.h b/arch/x86/include/asm/xen/interface.h index a93db16..555f94d 100644 --- a/arch/x86/include/asm/xen/interface.h +++ b/arch/x86/include/asm/xen/interface.h @@ -47,6 +47,10 @@ #endif #ifndef __ASSEMBLY__ +/* Explicitly size integers that represent pfns in the public interface

• • with Xen so that on ARM we can have one ABI that works for 32 and 64
• • bit guests. */

+typedef unsigned long xen_pfn_t; /* Guest handles for primitive C types. */ __DEFINE_GUEST_HANDLE(uchar, unsigned char); __DEFINE_GUEST_HANDLE(uint, unsigned int); @@ -57,6 +61,7 @@ DEFINE_GUEST_HANDLE(long); DEFINE_GUEST_HANDLE(void); DEFINE_GUEST_HANDLE(uint64_t); DEFINE_GUEST_HANDLE(uint32_t); +DEFINE_GUEST_HANDLE(xen_pfn_t); #endif #ifndef HYPERVISOR_VIRT_START diff --git a/include/xen/interface/grant_table.h b/include/xen/interface/grant_table.h index a17d844..7da811b 100644 --- a/include/xen/interface/grant_table.h +++ b/include/xen/interface/grant_table.h @@ -338,7 +338,7 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_dump_table); #define GNTTABOP_transfer 4 struct gnttab_transfer { /* IN parameters. */

• unsigned long mfn;

• xen_pfn_t mfn; domid_t domid; grant_ref_t ref; /* OUT parameters. */

@@ -375,7 +375,7 @@ struct gnttab_copy { struct { union { grant_ref_t ref;

• 	unsigned long   gmfn;
  

• 	xen_pfn_t   gmfn;
  

  } u; domid_t domid; uint16_t offset;

diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h index eac3ce1..abbbff0 100644 --- a/include/xen/interface/memory.h +++ b/include/xen/interface/memory.h @@ -31,7 +31,7 @@ struct xen_memory_reservation { * OUT: GMFN bases of extents that were allocated * (NB. This command also updates the mach_to_phys translation table) */

• GUEST_HANDLE(ulong) extent_start;

• GUEST_HANDLE(xen_pfn_t) extent_start;

/* Number of extents, and size/alignment of each (2^extent_order pages). */ unsigned long nr_extents; @@ -130,7 +130,7 @@ struct xen_machphys_mfn_list { * any large discontiguities in the machine address space, 2MB gaps in * the machphys table will be represented by an MFN base of zero. */

• GUEST_HANDLE(ulong) extent_start;

• GUEST_HANDLE(xen_pfn_t) extent_start;

/* * Number of extents written to the above array. This will be smaller @@ -172,7 +172,7 @@ struct xen_add_to_physmap { unsigned long idx; /* GPFN where the source mapping page should appear. */

• unsigned long gpfn;

• xen_pfn_t gpfn;

}; DEFINE_GUEST_HANDLE_STRUCT(xen_add_to_physmap); diff --git a/include/xen/interface/platform.h b/include/xen/interface/platform.h index 486653f..0bea470 100644 --- a/include/xen/interface/platform.h +++ b/include/xen/interface/platform.h @@ -54,7 +54,7 @@ DEFINE_GUEST_HANDLE_STRUCT(xenpf_settime_t); #define XENPF_add_memtype 31 struct xenpf_add_memtype { /* IN variables. */

• unsigned long mfn;

• xen_pfn_t mfn; uint64_t nr_mfns; uint32_t type; /* OUT variables. */

@@ -84,7 +84,7 @@ struct xenpf_read_memtype { /* IN variables. */ uint32_t reg; /* OUT variables. */

• unsigned long mfn;

• xen_pfn_t mfn; uint64_t nr_mfns; uint32_t type;

}; diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h index 3871e47..42834a3 100644 --- a/include/xen/interface/xen.h +++ b/include/xen/interface/xen.h @@ -188,7 +188,7 @@ struct mmuext_op { unsigned int cmd; union { /* [UN]PIN_TABLE, NEW_BASEPTR, NEW_USER_BASEPTR */

• unsigned long mfn;
  

• xen_pfn_t mfn;
  

  /* INVLPG_LOCAL, INVLPG_ALL, SET_LDT */ unsigned long linear_addr; } arg1;

@@ -428,11 +428,11 @@ struct start_info { unsigned long nr_pages; /* Total pages allocated to this domain. */ unsigned long shared_info; /* MACHINE address of shared info struct. */ uint32_t flags; /* SIF_xxx flags. */

• unsigned long store_mfn; /* MACHINE page number of shared page. */

• xen_pfn_t store_mfn; /* MACHINE page number of shared page. */ uint32_t store_evtchn; /* Event channel for store communication. */ union { struct {

• 	unsigned long mfn;  /* MACHINE page number of console page.   */
  

• 	xen_pfn_t mfn;      /* MACHINE page number of console page.   */
  uint32_t  evtchn;   /* Event channel for console page.        */
  

  } domU; struct {

diff --git a/include/xen/privcmd.h b/include/xen/privcmd.h index 4d58881..45c1aa1 100644 --- a/include/xen/privcmd.h +++ b/include/xen/privcmd.h @@ -37,8 +37,6 @@ #include <linux/compiler.h> #include <xen/interface/xen.h> -typedef unsigned long xen_pfn_t;

struct privcmd_hypercall { __u64 op; __u64 arg[5]; -- 1.7.2.5

On Mon, Aug 06, 2012 at 03:27:12PM +0100, Stefano Stabellini wrote:

All the original Xen headers have xen_ulong_t as unsigned long type, however when they have been imported in Linux, xen_ulong_t has been replaced with unsigned long. That might work for x86 and ia64 but it does not for arm. Bring back xen_ulong_t and let each architecture define xen_ulong_t as they see fit.

Also explicitly size pointers (__DEFINE_GUEST_HANDLE) to 64 bit.

Looks ok to me.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

arch/arm/include/asm/xen/interface.h | 8 ++++++-- arch/ia64/include/asm/xen/interface.h | 1 + arch/x86/include/asm/xen/interface.h | 1 + include/xen/interface/memory.h | 12 ++++++------ include/xen/interface/physdev.h | 4 ++-- include/xen/interface/version.h | 2 +- include/xen/interface/xen.h | 6 +++--- 7 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/arch/arm/include/asm/xen/interface.h b/arch/arm/include/asm/xen/interface.h index f904dcc..1d3030c 100644 --- a/arch/arm/include/asm/xen/interface.h +++ b/arch/arm/include/asm/xen/interface.h @@ -9,8 +9,11 @@ #include <linux/types.h> +#define uint64_aligned_t uint64_t __attribute__((aligned(8)))

#define __DEFINE_GUEST_HANDLE(name, type) \

• typedef type * __guest_handle_ ## name

• typedef struct { union { type *p; uint64_aligned_t q; }; } \

•    __guest_handle_ ## name
  

#define DEFINE_GUEST_HANDLE_STRUCT(name) \ __DEFINE_GUEST_HANDLE(name, struct name) @@ -21,13 +24,14 @@ do { \ if (sizeof(hnd) == 8) \ *(uint64_t *)&(hnd) = 0; \

• (hnd) = val;				\
  

• (hnd).p = val;				\
  

  } while (0)

#ifndef __ASSEMBLY__ /* Explicitly size integers that represent pfns in the interface with

• Xen so that we can have one ABI that works for 32 and 64 bit guests. */

typedef uint64_t xen_pfn_t; +typedef uint64_t xen_ulong_t; /* Guest handles for primitive C types. */ __DEFINE_GUEST_HANDLE(uchar, unsigned char); __DEFINE_GUEST_HANDLE(uint, unsigned int); diff --git a/arch/ia64/include/asm/xen/interface.h b/arch/ia64/include/asm/xen/interface.h index 686464e..7c83445 100644 --- a/arch/ia64/include/asm/xen/interface.h +++ b/arch/ia64/include/asm/xen/interface.h @@ -71,6 +71,7 @@

• with Xen so that we could have one ABI that works for 32 and 64 bit
• guests. */

typedef unsigned long xen_pfn_t; +typedef unsigned long xen_ulong_t; /* Guest handles for primitive C types. */ __DEFINE_GUEST_HANDLE(uchar, unsigned char); __DEFINE_GUEST_HANDLE(uint, unsigned int); diff --git a/arch/x86/include/asm/xen/interface.h b/arch/x86/include/asm/xen/interface.h index 555f94d..28fc621 100644 --- a/arch/x86/include/asm/xen/interface.h +++ b/arch/x86/include/asm/xen/interface.h @@ -51,6 +51,7 @@

• with Xen so that on ARM we can have one ABI that works for 32 and 64
• bit guests. */

typedef unsigned long xen_pfn_t; +typedef unsigned long xen_ulong_t; /* Guest handles for primitive C types. */ __DEFINE_GUEST_HANDLE(uchar, unsigned char); __DEFINE_GUEST_HANDLE(uint, unsigned int); diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h index abbbff0..b5c3098 100644 --- a/include/xen/interface/memory.h +++ b/include/xen/interface/memory.h @@ -34,7 +34,7 @@ struct xen_memory_reservation { GUEST_HANDLE(xen_pfn_t) extent_start; /* Number of extents, and size/alignment of each (2^extent_order pages). */

• unsigned long nr_extents;

• xen_ulong_t nr_extents; unsigned int extent_order;

/* @@ -92,7 +92,7 @@ struct xen_memory_exchange { * command will be non-zero. * 5. THIS FIELD MUST BE INITIALISED TO ZERO BY THE CALLER! */

• unsigned long nr_exchanged;

• xen_ulong_t nr_exchanged;

}; DEFINE_GUEST_HANDLE_STRUCT(xen_memory_exchange); @@ -148,8 +148,8 @@ DEFINE_GUEST_HANDLE_STRUCT(xen_machphys_mfn_list); */ #define XENMEM_machphys_mapping 12 struct xen_machphys_mapping {

• unsigned long v_start, v_end; /* Start and end virtual addresses. */
• unsigned long max_mfn; /* Maximum MFN that can be looked up. */

• xen_ulong_t v_start, v_end; /* Start and end virtual addresses. */
• xen_ulong_t max_mfn; /* Maximum MFN that can be looked up. */

}; DEFINE_GUEST_HANDLE_STRUCT(xen_machphys_mapping_t); @@ -169,7 +169,7 @@ struct xen_add_to_physmap { unsigned int space; /* Index into source mapping space. */

• unsigned long idx;

• xen_ulong_t idx;

/* GPFN where the source mapping page should appear. */ xen_pfn_t gpfn; @@ -186,7 +186,7 @@ struct xen_translate_gpfn_list { domid_t domid; /* Length of list. */

• unsigned long nr_gpfns;

• xen_ulong_t nr_gpfns;

/* List of GPFNs to translate. */ GUEST_HANDLE(ulong) gpfn_list; diff --git a/include/xen/interface/physdev.h b/include/xen/interface/physdev.h index 9ce788d..bc3ae14 100644 --- a/include/xen/interface/physdev.h +++ b/include/xen/interface/physdev.h @@ -56,7 +56,7 @@ struct physdev_eoi { #define PHYSDEVOP_pirq_eoi_gmfn_v2 28 struct physdev_pirq_eoi_gmfn { /* IN */

• unsigned long gmfn;

• xen_ulong_t gmfn;

}; /* @@ -108,7 +108,7 @@ struct physdev_set_iobitmap { #define PHYSDEVOP_apic_write 9 struct physdev_apic { /* IN */

• unsigned long apic_physbase;

• xen_ulong_t apic_physbase; uint32_t reg; /* IN or OUT */ uint32_t value;

diff --git a/include/xen/interface/version.h b/include/xen/interface/version.h index e8b6519..30280c9 100644 --- a/include/xen/interface/version.h +++ b/include/xen/interface/version.h @@ -45,7 +45,7 @@ struct xen_changeset_info { #define XENVER_platform_parameters 5 struct xen_platform_parameters {

• unsigned long virt_start;

• xen_ulong_t virt_start;

}; #define XENVER_get_features 6 diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h index 42834a3..ec32115 100644 --- a/include/xen/interface/xen.h +++ b/include/xen/interface/xen.h @@ -274,9 +274,9 @@ DEFINE_GUEST_HANDLE_STRUCT(mmu_update);

• NB. The fields are natural register size for this architecture.

*/ struct multicall_entry {

• unsigned long op;
• long result;
• unsigned long args[6];

• xen_ulong_t op;
• xen_ulong_t result;
• xen_ulong_t args[6];

}; DEFINE_GUEST_HANDLE_STRUCT(multicall_entry); -- 1.7.2.5

On 08/07/2012 02:21 PM, Konrad Rzeszutek Wilk wrote:

On Mon, Aug 06, 2012 at 03:27:13PM +0100, Stefano Stabellini wrote:

...

bind_evtchn_to_irqhandler can legitimately return 0 (irq 0): it is not an error.

If Linux is running as an HVM domain and is running as Dom0, use xenstored_local_init to initialize the xenstore page and event channel.

Changes in v2:

• refactor xenbus_init.

Thank you. Lets also CC our friend at NSA who has been doing some work in that area. Daniel are you OK with this change - will it still make PV initial domain with with the MiniOS XenBus driver?

Thanks.

That case will work, but what this will break is launching the initial domain with a Xenstore stub domain already running (see below).

...

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

drivers/xen/xenbus/xenbus_comms.c | 2 +- drivers/xen/xenbus/xenbus_probe.c | 62 +++++++++++++++++++++++++----------- drivers/xen/xenbus/xenbus_xs.c | 1 + 3 files changed, 45 insertions(+), 20 deletions(-)

diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c index 52fe7ad..c5aa55c 100644 --- a/drivers/xen/xenbus/xenbus_comms.c +++ b/drivers/xen/xenbus/xenbus_comms.c @@ -224,7 +224,7 @@ int xb_init_comms(void) int err; err = bind_evtchn_to_irqhandler(xen_store_evtchn, wake_waiting, 0, "xenbus", &xb_waitq);

• if (err <= 0) {
  

• if (err < 0) {
  printk(KERN_ERR "XENBUS request irq failed %i\n", err);
  return err;
  

  }

...

diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index b793723..a67ccc0 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -719,37 +719,61 @@ static int __init xenstored_local_init(void) return err; } +enum xenstore_init {

• UNKNOWN,
• PV,
• HVM,
• LOCAL,

+}; static int __init xenbus_init(void) { int err = 0;

• enum xenstore_init usage = UNKNOWN;
• uint64_t v = 0;

if (!xen_domain()) return -ENODEV; xenbus_ring_ops_init();

• if (xen_hvm_domain()) {

• uint64_t v = 0;
  

• err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
  

• if (err)
  

• 	goto out_error;
  

• xen_store_evtchn = (int)v;
  

• err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
  

• if (err)
  

• 	goto out_error;
  

• xen_store_mfn = (unsigned long)v;
  

• xen_store_interface = ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
  

• } else {

• xen_store_evtchn = xen_start_info->store_evtchn;
  

• xen_store_mfn = xen_start_info->store_mfn;
  

• if (xen_store_evtchn)
  

• 	xenstored_ready = 1;
  

• else {
  

• if (xen_pv_domain())

• usage = PV;
  

• if (xen_hvm_domain())

• usage = HVM;
  

The above is correct for domUs, and is overridden for dom0s:

...

• if (xen_hvm_domain() && xen_initial_domain())

• usage = LOCAL;
  

• if (xen_pv_domain() && !xen_start_info->store_evtchn)

• usage = LOCAL;
  

Instead of these checks, I think it should just be:

if (!xen_start_info->store_evtchn) usage = LOCAL;

Any domain started after xenstore will have store_evtchn set, so if you don't have this set, you are either going to be running xenstore locally, or will use the ioctl to change it later (and so should still set up everything as if it will be running locally).

...

• if (xen_pv_domain() && xen_start_info->store_evtchn)

• xenstored_ready = 1;
  

This part can now just be moved unconditionally into case PV.

...

• switch (usage) {

• case LOCAL:
  err = xenstored_local_init();
  if (err)
  	goto out_error;
  

• }
  

• xen_store_interface = mfn_to_virt(xen_store_mfn);
  

• 	xen_store_interface = mfn_to_virt(xen_store_mfn);
  

• 	break;
  

• case PV:
  

• 	xen_store_evtchn = xen_start_info->store_evtchn;
  

• 	xen_store_mfn = xen_start_info->store_mfn;
  

• 	xen_store_interface = mfn_to_virt(xen_store_mfn);
  

• 	break;
  

• case HVM:
  

• 	err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
  

• 	if (err)
  

• 		goto out_error;
  

• 	xen_store_evtchn = (int)v;
  

• 	err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
  

• 	if (err)
  

• 		goto out_error;
  

• 	xen_store_mfn = (unsigned long)v;
  

• 	xen_store_interface =
  

• 		ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
  

• 	break;
  

• default:
  

• 	pr_warn("Xenstore state unknown\n");
  

• 	break;
  

  }

/* Initialize the interface to xenstore. */ diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c index d1c217b..f7feb3d 100644 --- a/drivers/xen/xenbus/xenbus_xs.c +++ b/drivers/xen/xenbus/xenbus_xs.c @@ -44,6 +44,7 @@ #include <linux/rwsem.h> #include <linux/module.h> #include <linux/mutex.h> +#include <asm/xen/hypervisor.h> #include <xen/xenbus.h> #include <xen/xen.h>

#include "xenbus_comms.h"

1.7.2.5

On 08/08/2012 12:51 PM, Stefano Stabellini wrote:

On Tue, 7 Aug 2012, Daniel De Graaf wrote:

...

On 08/07/2012 02:21 PM, Konrad Rzeszutek Wilk wrote:

...

On Mon, Aug 06, 2012 at 03:27:13PM +0100, Stefano Stabellini wrote:

...

bind_evtchn_to_irqhandler can legitimately return 0 (irq 0): it is not an error.

If Linux is running as an HVM domain and is running as Dom0, use xenstored_local_init to initialize the xenstore page and event channel.

Changes in v2:

• refactor xenbus_init.

Thank you. Lets also CC our friend at NSA who has been doing some work in that area. Daniel are you OK with this change - will it still make PV initial domain with with the MiniOS XenBus driver?

Thanks.

That case will work, but what this will break is launching the initial domain with a Xenstore stub domain already running (see below).

...

...

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

drivers/xen/xenbus/xenbus_comms.c | 2 +- drivers/xen/xenbus/xenbus_probe.c | 62 +++++++++++++++++++++++++----------- drivers/xen/xenbus/xenbus_xs.c | 1 + 3 files changed, 45 insertions(+), 20 deletions(-)

diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c index 52fe7ad..c5aa55c 100644 --- a/drivers/xen/xenbus/xenbus_comms.c +++ b/drivers/xen/xenbus/xenbus_comms.c @@ -224,7 +224,7 @@ int xb_init_comms(void) int err; err = bind_evtchn_to_irqhandler(xen_store_evtchn, wake_waiting, 0, "xenbus", &xb_waitq);

• if (err <= 0) {
  

• if (err < 0) {
  printk(KERN_ERR "XENBUS request irq failed %i\n", err);
  return err;
  

  }

...

diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index b793723..a67ccc0 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -719,37 +719,61 @@ static int __init xenstored_local_init(void) return err; } +enum xenstore_init {

• UNKNOWN,
• PV,
• HVM,
• LOCAL,

+}; static int __init xenbus_init(void) { int err = 0;

• enum xenstore_init usage = UNKNOWN;
• uint64_t v = 0;

if (!xen_domain()) return -ENODEV; xenbus_ring_ops_init();

• if (xen_hvm_domain()) {

• uint64_t v = 0;
  

• err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
  

• if (err)
  

• 	goto out_error;
  

• xen_store_evtchn = (int)v;
  

• err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
  

• if (err)
  

• 	goto out_error;
  

• xen_store_mfn = (unsigned long)v;
  

• xen_store_interface = ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
  

• } else {

• xen_store_evtchn = xen_start_info->store_evtchn;
  

• xen_store_mfn = xen_start_info->store_mfn;
  

• if (xen_store_evtchn)
  

• 	xenstored_ready = 1;
  

• else {
  

• if (xen_pv_domain())

• usage = PV;
  

• if (xen_hvm_domain())

• usage = HVM;
  

The above is correct for domUs, and is overridden for dom0s:

...

...

• if (xen_hvm_domain() && xen_initial_domain())

• usage = LOCAL;
  

• if (xen_pv_domain() && !xen_start_info->store_evtchn)

• usage = LOCAL;
  

Instead of these checks, I think it should just be:

if (!xen_start_info->store_evtchn) usage = LOCAL;

Any domain started after xenstore will have store_evtchn set, so if you don't have this set, you are either going to be running xenstore locally, or will use the ioctl to change it later (and so should still set up everything as if it will be running locally).

That would be wrong for an HVM dom0 domain (at least on ARM), because we don't have a start_info page at all.

...

...

...

• if (xen_pv_domain() && xen_start_info->store_evtchn)

• xenstored_ready = 1;
  

This part can now just be moved unconditionally into case PV.

What about:

if (xen_pv_domain()) usage = PV; if (xen_hvm_domain()) usage = HVM; if (!xen_store_evtchn) usage = LOCAL;

and moving xenstored_ready in case PV, like you suggested.

That looks correct, but you'd need to split up the switch statement in order to populate xen_store_evtchn before that last condition, which ends up pretty much eliminating the usage variable.

On 08/08/2012 01:19 PM, Stefano Stabellini wrote:

On Wed, 8 Aug 2012, Daniel De Graaf wrote:

...

On 08/08/2012 12:51 PM, Stefano Stabellini wrote:

...

On Tue, 7 Aug 2012, Daniel De Graaf wrote:

...

On 08/07/2012 02:21 PM, Konrad Rzeszutek Wilk wrote:

...

On Mon, Aug 06, 2012 at 03:27:13PM +0100, Stefano Stabellini wrote:

...

bind_evtchn_to_irqhandler can legitimately return 0 (irq 0): it is not an error.

If Linux is running as an HVM domain and is running as Dom0, use xenstored_local_init to initialize the xenstore page and event channel.

Changes in v2:

• refactor xenbus_init.

Thank you. Lets also CC our friend at NSA who has been doing some work in that area. Daniel are you OK with this change - will it still make PV initial domain with with the MiniOS XenBus driver?

Thanks.

That case will work, but what this will break is launching the initial domain with a Xenstore stub domain already running (see below).

...

...

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

drivers/xen/xenbus/xenbus_comms.c | 2 +- drivers/xen/xenbus/xenbus_probe.c | 62 +++++++++++++++++++++++++----------- drivers/xen/xenbus/xenbus_xs.c | 1 + 3 files changed, 45 insertions(+), 20 deletions(-)

diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c index 52fe7ad..c5aa55c 100644 --- a/drivers/xen/xenbus/xenbus_comms.c +++ b/drivers/xen/xenbus/xenbus_comms.c @@ -224,7 +224,7 @@ int xb_init_comms(void) int err; err = bind_evtchn_to_irqhandler(xen_store_evtchn, wake_waiting, 0, "xenbus", &xb_waitq);

• if (err <= 0) {
  

• if (err < 0) {
  printk(KERN_ERR "XENBUS request irq failed %i\n", err);
  return err;
  

  }

...

diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index b793723..a67ccc0 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -719,37 +719,61 @@ static int __init xenstored_local_init(void) return err; } +enum xenstore_init {

• UNKNOWN,
• PV,
• HVM,
• LOCAL,

+}; static int __init xenbus_init(void) { int err = 0;

• enum xenstore_init usage = UNKNOWN;
• uint64_t v = 0;

if (!xen_domain()) return -ENODEV; xenbus_ring_ops_init();

• if (xen_hvm_domain()) {

• uint64_t v = 0;
  

• err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
  

• if (err)
  

• 	goto out_error;
  

• xen_store_evtchn = (int)v;
  

• err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v);
  

• if (err)
  

• 	goto out_error;
  

• xen_store_mfn = (unsigned long)v;
  

• xen_store_interface = ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
  

• } else {

• xen_store_evtchn = xen_start_info->store_evtchn;
  

• xen_store_mfn = xen_start_info->store_mfn;
  

• if (xen_store_evtchn)
  

• 	xenstored_ready = 1;
  

• else {
  

• if (xen_pv_domain())

• usage = PV;
  

• if (xen_hvm_domain())

• usage = HVM;
  

The above is correct for domUs, and is overridden for dom0s:

...

...

• if (xen_hvm_domain() && xen_initial_domain())

• usage = LOCAL;
  

• if (xen_pv_domain() && !xen_start_info->store_evtchn)

• usage = LOCAL;
  

Instead of these checks, I think it should just be:

if (!xen_start_info->store_evtchn) usage = LOCAL;

Any domain started after xenstore will have store_evtchn set, so if you don't have this set, you are either going to be running xenstore locally, or will use the ioctl to change it later (and so should still set up everything as if it will be running locally).

That would be wrong for an HVM dom0 domain (at least on ARM), because we don't have a start_info page at all.

...

...

...

• if (xen_pv_domain() && xen_start_info->store_evtchn)

• xenstored_ready = 1;
  

This part can now just be moved unconditionally into case PV.

What about:

if (xen_pv_domain()) usage = PV; if (xen_hvm_domain()) usage = HVM; if (!xen_store_evtchn) usage = LOCAL;

and moving xenstored_ready in case PV, like you suggested.

That looks correct, but you'd need to split up the switch statement in order to populate xen_store_evtchn before that last condition, which ends up pretty much eliminating the usage variable.

Going back to what you wrote in the previous email, in what way this patch breaks the case when an initial domain is started after a Xenstore stub domain?

Assuming that we are talking about a PV initial domain on x86, the following check

if (xen_pv_domain() && !xen_start_info->store_evtchn) usage = LOCAL;

will return false (because store_evtchn is set), therefore usage will remain set to PV. And the check:

if (xen_pv_domain() && xen_start_info->store_evtchn) xenstored_ready = 1;

will return true so xenstored_ready is going to be set to 1.

Right, the original patch didn't break anything with PV domains. The case it doesn't handle is an HVM initial domain with an already-running Xenstore domain; I think this applies both to ARM and hybrid/PVH on x86. In that case, usage would be set to LOCAL instead of HVM.

As a side note: the value of xen_initial_domain() shouldn't be connected to determining if xenstore is running locally or not.

On Mon, Aug 06, 2012 at 03:27:14PM +0100, Stefano Stabellini wrote:

Changes in v2:

• make pci.o depend on CONFIG_PCI and acpi.o depend on CONFIG_ACPI.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

Looks good.

---

drivers/xen/Makefile | 11 ++++++++--- 1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index fc34886..bee02b2 100644 --- a/drivers/xen/Makefile +++ b/drivers/xen/Makefile @@ -1,11 +1,17 @@ -obj-y += grant-table.o features.o events.o manage.o balloon.o +ifneq ($(CONFIG_ARM),y) +obj-y += manage.o balloon.o +obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o +endif +obj-y += grant-table.o features.o events.o obj-y += xenbus/ nostackp := $(call cc-option, -fno-stack-protector) CFLAGS_features.o := $(nostackp) +obj-$(CONFIG_XEN_DOM0) += $(dom0-y) +dom0-$(CONFIG_PCI) := pci.o +dom0-$(CONFIG_ACPI) := acpi.o obj-$(CONFIG_BLOCK) += biomerge.o -obj-$(CONFIG_HOTPLUG_CPU) += cpu_hotplug.o obj-$(CONFIG_XEN_XENCOMM) += xencomm.o obj-$(CONFIG_XEN_BALLOON) += xen-balloon.o obj-$(CONFIG_XEN_SELFBALLOONING) += xen-selfballoon.o @@ -17,7 +23,6 @@ obj-$(CONFIG_XEN_SYS_HYPERVISOR) += sys-hypervisor.o obj-$(CONFIG_XEN_PVHVM) += platform-pci.o obj-$(CONFIG_XEN_TMEM) += tmem.o obj-$(CONFIG_SWIOTLB_XEN) += swiotlb-xen.o -obj-$(CONFIG_XEN_DOM0) += pci.o acpi.o obj-$(CONFIG_XEN_PCIDEV_BACKEND) += xen-pciback/ obj-$(CONFIG_XEN_PRIVCMD) += xen-privcmd.o obj-$(CONFIG_XEN_ACPI_PROCESSOR) += xen-acpi-processor.o -- 1.7.2.5

On Mon, Aug 06, 2012 at 03:27:15PM +0100, Stefano Stabellini wrote:

Changes in v2:

• mark Xen guest support on ARM as EXPERIMENTAL.

OK. Looks good.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

arch/arm/Kconfig | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index a91009c..f14664b 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1855,6 +1855,16 @@ config DEPRECATED_PARAM_STRUCT This was deprecated in 2001 and announced to live on for 5 years. Some old boot loaders still use this way. +config XEN_DOM0

• def_bool y

+config XEN

• bool "Xen guest support on ARM (EXPERIMENTAL)"
• depends on EXPERIMENTAL && ARM && OF
• select XEN_DOM0
• help

•  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
  

endmenu menu "Boot options" -- 1.7.2.5

On Mon, Aug 06, 2012 at 03:27:16PM +0100, Stefano Stabellini wrote:

Use Xen features to figure out if we are privileged.

XENFEAT_dom0 was introduced by 23735 in xen-unstable.hg.

Looks good.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

arch/arm/xen/enlighten.c | 7 +++++++ include/xen/interface/features.h | 3 +++ 2 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 102d823..ac3a2d6 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -1,6 +1,7 @@ #include <xen/xen.h> #include <xen/interface/xen.h> #include <xen/interface/memory.h> +#include <xen/features.h> #include <xen/platform_pci.h> #include <asm/xen/hypervisor.h> #include <asm/xen/hypercall.h> @@ -57,6 +58,12 @@ static int __init xen_guest_init(void) } xen_domain_type = XEN_HVM_DOMAIN;

• xen_setup_features();
• if (xen_feature(XENFEAT_dom0))

• xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
  

• else

• xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED);
  

• if (!shared_info_page) shared_info_page = (struct shared_info *) get_zeroed_page(GFP_KERNEL);

diff --git a/include/xen/interface/features.h b/include/xen/interface/features.h index b6ca39a..131a6cc 100644 --- a/include/xen/interface/features.h +++ b/include/xen/interface/features.h @@ -50,6 +50,9 @@ /* x86: pirq can be used by HVM guests */ #define XENFEAT_hvm_pirqs 10 +/* operation as Dom0 is supported */ +#define XENFEAT_dom0 11

#define XENFEAT_NR_SUBMAPS 1

#endif /* __XEN_PUBLIC_FEATURES_H__ */

1.7.2.5

On Tue, 7 Aug 2012, Konrad Rzeszutek Wilk wrote:

On Mon, Aug 06, 2012 at 03:27:18PM +0100, Stefano Stabellini wrote:

...

Compile events.c on ARM. Parse, map and enable the IRQ to get event notifications from the device tree (node "/xen").

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

arch/arm/include/asm/xen/events.h | 18 ++++++++++++++++++ arch/arm/xen/enlighten.c | 33 +++++++++++++++++++++++++++++++++ arch/x86/xen/enlighten.c | 1 + arch/x86/xen/irq.c | 1 + arch/x86/xen/xen-ops.h | 1 - drivers/xen/events.c | 17 ++++++++++++++--- include/xen/events.h | 2 ++ 7 files changed, 69 insertions(+), 4 deletions(-) create mode 100644 arch/arm/include/asm/xen/events.h

diff --git a/arch/arm/include/asm/xen/events.h b/arch/arm/include/asm/xen/events.h new file mode 100644 index 0000000..94b4e90 --- /dev/null +++ b/arch/arm/include/asm/xen/events.h @@ -0,0 +1,18 @@ +#ifndef _ASM_ARM_XEN_EVENTS_H +#define _ASM_ARM_XEN_EVENTS_H

+#include <asm/ptrace.h>

+enum ipi_vector {

• XEN_PLACEHOLDER_VECTOR,
• /* Xen IPIs go here */
• XEN_NR_IPIS,

+};

+static inline int xen_irqs_disabled(struct pt_regs *regs) +{

• return raw_irqs_disabled_flags(regs->ARM_cpsr);

+}

+#endif /* _ASM_ARM_XEN_EVENTS_H */ diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index e5e92d5..87b17f0 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -1,4 +1,5 @@ #include <xen/xen.h> +#include <xen/events.h> #include <xen/grant_table.h> #include <xen/hvm.h> #include <xen/interface/xen.h> @@ -9,6 +10,8 @@ #include <xen/xenbus.h> #include <asm/xen/hypervisor.h> #include <asm/xen/hypercall.h> +#include <linux/interrupt.h> +#include <linux/irqreturn.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_irq.h> @@ -33,6 +36,8 @@ EXPORT_SYMBOL_GPL(xen_have_vector_callback); int xen_platform_pci_unplug = XEN_UNPLUG_ALL; EXPORT_SYMBOL_GPL(xen_platform_pci_unplug); +static __read_mostly int xen_events_irq = -1;

So this is global..

...

int xen_remap_domain_mfn_range(struct vm_area_struct *vma, unsigned long addr, unsigned long mfn, int nr, @@ -66,6 +71,9 @@ static int __init xen_guest_init(void) if (of_address_to_resource(node, GRANT_TABLE_PHYSADDR, &res)) return 0; xen_hvm_resume_frames = res.start >> PAGE_SHIFT;

• xen_events_irq = irq_of_parse_and_map(node, 0);
• pr_info("Xen support found, events_irq=%d gnttab_frame_pfn=%lx\n",

• 	xen_events_irq, xen_hvm_resume_frames);
  

  xen_domain_type = XEN_HVM_DOMAIN;

xen_setup_features(); @@ -107,3 +115,28 @@ static int __init xen_guest_init(void) return 0; } core_initcall(xen_guest_init);

+static irqreturn_t xen_arm_callback(int irq, void *arg) +{

• xen_hvm_evtchn_do_upcall();
• return IRQ_HANDLED;

+}

+static int __init xen_init_events(void) +{

• if (!xen_domain() || xen_events_irq < 0)

• return -ENODEV;
  

• xen_init_IRQ();
• if (request_percpu_irq(xen_events_irq, xen_arm_callback,

• 	"events", xen_vcpu)) {
  

But here you are asking for it to be percpu? What if there are other interrupts on the _other_ CPUs that conflict with it?

...

• pr_err("Error requesting IRQ %d\n", xen_events_irq);
  

• return -EINVAL;
  

• }
• enable_percpu_irq(xen_events_irq, 0);

Uh, that is bold. One global to rule them all, eh? Should you make it at least: static DEFINE_PER_CPU(int, xen_events_irq); ?

That is an interesting observation.

Currently Xen is using a per-cpu interrupt (a PPI, using the GIC terminology), and it makes sense so that we can receive event notifications on multiple vcpus independently. The irq range 16-31 is reserved for PPIs and I am assuming that Xen will be able to find one spare, the same one, for all vcpus. In fact the third field corresponding to the interrupt in the DT (0xf08 in my dts) contains the cpu mask and it is set to 0xf (the maximum) right now.

Maybe I should just BUG_ON(xen_events_irq > 31 || xen_events_irq < 16)?

The versioning of the hypervisor node on the DT is going to help us make any changes to the interface in the future.

On Mon, Aug 06, 2012 at 03:27:19PM +0100, Stefano Stabellini wrote:

Reset the IRQ_NOAUTOEN and IRQ_NOREQUEST flags that are enabled by default on ARM. If IRQ_NOAUTOEN is set, __setup_irq doesn't call irq_startup, that is responsible for calling irq_unmask at startup time. As a result event channels remain masked.

Acked by me.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

drivers/xen/events.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 5ecb596..8ffb7b7 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -836,6 +836,7 @@ int bind_evtchn_to_irq(unsigned int evtchn) struct irq_info *info = info_for_irq(irq); WARN_ON(info == NULL || info->type != IRQT_EVTCHN); }

• irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN);

out: mutex_unlock(&irq_mapping_update_lock); -- 1.7.2.5

On Mon, Aug 06, 2012 at 03:27:20PM +0100, Stefano Stabellini wrote:

Only until we get the balloon driver to work.

OK. Acked-by be.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

arch/arm/xen/enlighten.c | 18 ++++++++++++++++++ 1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 87b17f0..c244583 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -140,3 +140,21 @@ static int __init xen_init_events(void) return 0; } postcore_initcall(xen_init_events);

+/* XXX: only until balloon is properly working */ +int alloc_xenballooned_pages(int nr_pages, struct page **pages, bool highmem) +{

• *pages = alloc_pages(highmem ? GFP_HIGHUSER : GFP_KERNEL,

• 	get_order(nr_pages));
  

• if (*pages == NULL)

• return -ENOMEM;
  

• return 0;

+} +EXPORT_SYMBOL_GPL(alloc_xenballooned_pages);

+void free_xenballooned_pages(int nr_pages, struct page **pages) +{

• kfree(*pages);
• *pages = NULL;

+}

+EXPORT_SYMBOL_GPL(free_xenballooned_pages);

1.7.2.5

On Mon, Aug 06, 2012 at 03:27:21PM +0100, Stefano Stabellini wrote:

This patch removes the "return -ENOSYS" for auto_translated_physmap guests from privcmd_mmap, thus it allows ARM guests to issue privcmd mmap calls. However privcmd mmap calls are still going to fail for HVM and hybrid guests on x86 because the xen_remap_domain_mfn_range implementation is currently PV only.

Looks good. Ack from me.

Changes in v2:

• better commit message;
• return -EINVAL from xen_remap_domain_mfn_range if auto_translated_physmap.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

arch/x86/xen/mmu.c | 3 +++ drivers/xen/privcmd.c | 4 ---- 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 3a73785..885a223 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -2310,6 +2310,9 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma, unsigned long range; int err = 0;

• if (xen_feature(XENFEAT_auto_translated_physmap))

• return -EINVAL;
  

• prot = __pgprot(pgprot_val(prot) | _PAGE_IOMAP);

BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_RESERVED | VM_IO)) == diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index ccee0f1..85226cb 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -380,10 +380,6 @@ static struct vm_operations_struct privcmd_vm_ops = { static int privcmd_mmap(struct file *file, struct vm_area_struct *vma) {

• /* Unsupported for auto-translate guests. */
• if (xen_feature(XENFEAT_auto_translated_physmap))

• return -ENOSYS;
  

• /* DONTCOPY is essential for Xen because copy_page_range doesn't know
  • how to recreate these mappings */
  vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY | VM_PFNMAP;

-- 1.7.2.5

On Mon, Aug 06, 2012 at 03:27:22PM +0100, Stefano Stabellini wrote:

OK. Looks good.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

drivers/block/xen-blkback/blkback.c | 1 + include/xen/interface/io/protocols.h | 3 +++ 2 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index 73f196c..63dd5b9 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -42,6 +42,7 @@ #include <xen/events.h> #include <xen/page.h> +#include <xen/xen.h> #include <asm/xen/hypervisor.h> #include <asm/xen/hypercall.h> #include "common.h" diff --git a/include/xen/interface/io/protocols.h b/include/xen/interface/io/protocols.h index 01fc8ae..0eafaf2 100644 --- a/include/xen/interface/io/protocols.h +++ b/include/xen/interface/io/protocols.h @@ -5,6 +5,7 @@ #define XEN_IO_PROTO_ABI_X86_64 "x86_64-abi" #define XEN_IO_PROTO_ABI_IA64 "ia64-abi" #define XEN_IO_PROTO_ABI_POWERPC64 "powerpc64-abi" +#define XEN_IO_PROTO_ABI_ARM "arm-abi" #if defined(__i386__) # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_X86_32 @@ -14,6 +15,8 @@ # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_IA64 #elif defined(__powerpc64__) # define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_POWERPC64 +#elif defined(__arm__) +# define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_ARM #else # error arch fixup needed here

#endif

1.7.2.5

On Mon, Aug 06, 2012 at 03:27:23PM +0100, Stefano Stabellini wrote:

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

OK. Looks good.

---

arch/arm/include/asm/xen/hypercall.h | 19 +++++++++++++++++++ drivers/net/xen-netback/netback.c | 1 + drivers/net/xen-netfront.c | 1 + 3 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/arch/arm/include/asm/xen/hypercall.h b/arch/arm/include/asm/xen/hypercall.h index 4ac0624..8a82325 100644 --- a/arch/arm/include/asm/xen/hypercall.h +++ b/arch/arm/include/asm/xen/hypercall.h @@ -47,4 +47,23 @@ unsigned long HYPERVISOR_hvm_op(int op, void *arg); int HYPERVISOR_memory_op(unsigned int cmd, void *arg); int HYPERVISOR_physdev_op(int cmd, void *arg); +static inline void +MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,

• 	unsigned int new_val, unsigned long flags)
  

+{

• BUG();

+}

+static inline void +MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,

•  int count, int *success_count, domid_t domid)
  

+{

• BUG();

+}

+static inline int +HYPERVISOR_multicall(void *call_list, int nr_calls) +{

• BUG();

+} #endif /* _ASM_ARM_XEN_HYPERCALL_H */ diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index f4a6fca..ab4f81c 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -40,6 +40,7 @@ #include <net/tcp.h> +#include <xen/xen.h> #include <xen/events.h> #include <xen/interface/memory.h> diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 3089990..bf4ba2b 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -43,6 +43,7 @@ #include <linux/slab.h> #include <net/ip.h> +#include <asm/xen/page.h> #include <xen/xen.h> #include <xen/xenbus.h>

#include <xen/events.h>

1.7.2.5

On Mon, Aug 06, 2012 at 03:27:24PM +0100, Stefano Stabellini wrote:

Update struct xen_add_to_physmap to be in sync with Xen's version of the structure. The size field was introduced by:

changeset: 24164:707d27fe03e7 user: Jean Guyader jean.guyader@eu.citrix.com date: Fri Nov 18 13:42:08 2011 +0000 summary: mm: New XENMEM space, XENMAPSPACE_gmfn_range

According to the comment:

"This new field .size is located in the 16 bits padding between .domid and .space in struct xen_add_to_physmap to stay compatible with older versions."

Changes in v2:

Looks good. Let me take this as in my tree to prep it for Mukesh's patches.

• remove erroneous comment in the commit message.

Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

include/xen/interface/memory.h | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h index b5c3098..b66d04c 100644 --- a/include/xen/interface/memory.h +++ b/include/xen/interface/memory.h @@ -163,6 +163,9 @@ struct xen_add_to_physmap { /* Which domain to change the mapping for. */ domid_t domid;

• /* Number of pages to go through for gmfn_range */
• uint16_t size;
• /* Source mapping space. */

#define XENMAPSPACE_shared_info 0 /* shared info page */

#define XENMAPSPACE_grant_table 1 /* grant table page */

1.7.2.5

On Mon, Aug 06, 2012 at 03:27:26PM +0100, Stefano Stabellini wrote:

From: Ian Campbell Ian.Campbell@citrix.com

Do not apply!

OK.

This is a simple, hacky implementation of xen_remap_domain_mfn_range, using XENMAPSPACE_gmfn_foreign.

It should use same interface as hybrid x86.

Yeah, Mukesh - can you share your patch here please?

Changes in v2:

• retain binary compatibility in xen_add_to_physmap: use a union.

Signed-off-by: Ian Campbell Ian.Campbell@citrix.com Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com

---

arch/arm/xen/enlighten.c | 79 +++++++++++++++++++++++++++++++++++++++- drivers/xen/privcmd.c | 16 +++++---- drivers/xen/xenfs/super.c | 7 ++++ include/xen/interface/memory.h | 15 ++++++-- 4 files changed, 105 insertions(+), 12 deletions(-)

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index c244583..20ca1e4 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -16,6 +16,10 @@ #include <linux/of.h> #include <linux/of_irq.h> #include <linux/of_address.h> +#include <linux/mm.h> +#include <linux/ioport.h>

+#include <asm/pgtable.h> struct start_info _xen_start_info; struct start_info *xen_start_info = &_xen_start_info; @@ -38,12 +42,85 @@ EXPORT_SYMBOL_GPL(xen_platform_pci_unplug); static __read_mostly int xen_events_irq = -1; +#define FOREIGN_MAP_BUFFER 0x90000000UL +#define FOREIGN_MAP_BUFFER_SIZE 0x10000000UL +struct resource foreign_map_resource = {

• .start = FOREIGN_MAP_BUFFER,
• .end = FOREIGN_MAP_BUFFER + FOREIGN_MAP_BUFFER_SIZE,
• .name = "Xen foreign map buffer",
• .flags = 0,

+};

+static unsigned long foreign_map_buffer_pfn = FOREIGN_MAP_BUFFER >> PAGE_SHIFT;

+struct remap_data {

• struct mm_struct *mm;
• unsigned long mfn;
• pgprot_t prot;

+};

+static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token,

• 		 unsigned long addr, void *data)
  

+{

• struct remap_data *rmd = data;
• pte_t pte = pfn_pte(rmd->mfn, rmd->prot);
• if (rmd->mfn < 0x90010)

• pr_crit("%s: ptep %p addr %#lx => %#x / %#lx\n",
  

•        __func__, ptep, addr, pte_val(pte), rmd->mfn);
  

• set_pte_at(rmd->mm, addr, ptep, pte);
• rmd->mfn++;
• return 0;

+}

int xen_remap_domain_mfn_range(struct vm_area_struct *vma, unsigned long addr, unsigned long mfn, int nr, pgprot_t prot, unsigned domid) {

• return -ENOSYS;

• int i, rc = 0;
• struct remap_data rmd = {

• .mm = vma->vm_mm,
  

• .prot = prot,
  

• };
• struct xen_add_to_physmap xatp = {

• .domid = DOMID_SELF,
  

• .space = XENMAPSPACE_gmfn_foreign,
  

• .foreign_domid = domid,
  

• };
• if (foreign_map_buffer_pfn + nr > ((FOREIGN_MAP_BUFFER +

• 			FOREIGN_MAP_BUFFER_SIZE)>>PAGE_SHIFT)) {
  

• pr_crit("RAM out of foreign map buffers...\n");
  

• return -EBUSY;
  

• }
• for (i = 0; i < nr; i++) {

• xatp.idx = mfn + i;
  

• xatp.gpfn = foreign_map_buffer_pfn + i;
  

• rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
  

• if (rc != 0) {
  

• 	pr_crit("foreign map add_to_physmap failed, err=%d\n", rc);
  

• 	goto out;
  

• }
  

• }
• rmd.mfn = foreign_map_buffer_pfn;
• rc = apply_to_page_range(vma->vm_mm,

• 		 addr,
  

• 		 (unsigned long)nr << PAGE_SHIFT,
  

• 		 remap_area_mfn_pte_fn, &rmd);
  

• if (rc != 0) {

• pr_crit("apply_to_page_range failed rc=%d\n", rc);
  

• goto out;
  

• }
• foreign_map_buffer_pfn += nr;

+out:

• return rc;

} EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range); diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index 85226cb..3e15c22 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -20,6 +20,8 @@ #include <linux/pagemap.h> #include <linux/seq_file.h> #include <linux/miscdevice.h> +#include <linux/resource.h> +#include <linux/ioport.h> #include <asm/pgalloc.h> #include <asm/pgtable.h> @@ -196,9 +198,6 @@ static long privcmd_ioctl_mmap(void __user *udata) LIST_HEAD(pagelist); struct mmap_mfn_state state;

• if (!xen_initial_domain())

• return -EPERM;
  

• if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd))) return -EFAULT;

@@ -286,9 +285,6 @@ static long privcmd_ioctl_mmap_batch(void __user *udata) LIST_HEAD(pagelist); struct mmap_batch_state state;

• if (!xen_initial_domain())

• return -EPERM;
  

• if (copy_from_user(&m, udata, sizeof(m))) return -EFAULT;

@@ -365,6 +361,11 @@ static long privcmd_ioctl(struct file *file, return ret; } +static void privcmd_close(struct vm_area_struct *vma) +{

• /* TODO: unmap VMA */

+}

static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n", @@ -375,7 +376,8 @@ static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf) } static struct vm_operations_struct privcmd_vm_ops = {

• .fault = privcmd_fault

• .fault = privcmd_fault,
• .close = privcmd_close,

}; static int privcmd_mmap(struct file *file, struct vm_area_struct *vma) diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c index a84b53c..edbe22f 100644 --- a/drivers/xen/xenfs/super.c +++ b/drivers/xen/xenfs/super.c @@ -12,6 +12,7 @@ #include <linux/module.h> #include <linux/fs.h> #include <linux/magic.h> +#include <linux/ioport.h> #include <xen/xen.h> @@ -80,6 +81,8 @@ static const struct file_operations capabilities_file_ops = { .llseek = default_llseek, }; +extern struct resource foreign_map_resource;

static int xenfs_fill_super(struct super_block *sb, void *data, int silent) { static struct tree_descr xenfs_files[] = { @@ -100,6 +103,10 @@ static int xenfs_fill_super(struct super_block *sb, void *data, int silent) &xsd_kva_file_ops, NULL, S_IRUSR|S_IWUSR); xenfs_create_file(sb, sb->s_root, "xsd_port", &xsd_port_file_ops, NULL, S_IRUSR|S_IWUSR);

• rc = request_resource(&iomem_resource, &foreign_map_resource);
  

• if (rc < 0)
  

• 	pr_crit("failed to register foreign map resource\n");
  

• rc = 0; /* ignore */
  

  }

return rc; diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h index b66d04c..dd2ffe0 100644 --- a/include/xen/interface/memory.h +++ b/include/xen/interface/memory.h @@ -163,12 +163,19 @@ struct xen_add_to_physmap { /* Which domain to change the mapping for. */ domid_t domid;

• /* Number of pages to go through for gmfn_range */
• uint16_t size;

• union {

•    /* Number of pages to go through for gmfn_range */
  

•    uint16_t    size;
  

•    /* IFF gmfn_foreign */
  

•    domid_t foreign_domid;
  

• };

/* Source mapping space. */ -#define XENMAPSPACE_shared_info 0 /* shared info page */ -#define XENMAPSPACE_grant_table 1 /* grant table page */ +#define XENMAPSPACE_shared_info 0 /* shared info page */ +#define XENMAPSPACE_grant_table 1 /* grant table page */ +#define XENMAPSPACE_gmfn 2 /* GMFN */ +#define XENMAPSPACE_gmfn_range 3 /* GMFN range */ +#define XENMAPSPACE_gmfn_foreign 4 /* GMFN from another guest */ unsigned int space; /* Index into source mapping space. */ -- 1.7.2.5