Re: [PATCH v2 2/3] ARM/ARM64: KVM: Add support for PSCI v0.2 emulation

Hi Mark,

On Mon, Feb 3, 2014 at 4:24 PM, Mark Rutland mark.rutland@arm.com wrote:

On Thu, Jan 30, 2014 at 10:41:18AM +0000, Anup Patel wrote:

...

Currently, the in-kernel PSCI emulation provides PSCI v0.1 interface to VCPUs. This patch extends current in-kernel PSCI emulation to provide PSCI v0.2 interface to VCPUs.

By default, ARM/ARM64 KVM will always provide PSCI v0.1 interface for keeping the ABI backward-compatible.

To select PSCI v0.2 interface for VCPUs, the user space (i.e. QEMU or KVMTOOL) will have to set KVM_ARM_VCPU_PSCI_0_2 feature when doing VCPU init using KVM_ARM_VCPU_INIT ioctl.

I have an issue with this. PSCI 0.2 makes all but two functions (MIGRATE and MIGRATE_INFO_CPU_UP) mandatory, and hence not allowed to return NOT_SUPPORTED.

Additionally, for correct behaviour across a kexec in future, we'll require AFFINITY_INFO for PSCI 0.2+ systems to determint when a CPU is actually dead (and cannot affect the cache hierarchy). I'd very much like to make that a hard requirement to ensure correctness.

I would very much like to see at least trivial implementations of those mandatory functions, so that we don't need a KVM_ARM_VCPU_PSCI_REALLY_0_2 or similar in future. As it stands this series does not implement PSCI 0.2.

The intention behind this series was to provide a base implementation of PSCI v0.2 which can be extended by subsequent patches that implement other PSCI v0.2 functions.

I already have a patch series that implement PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET based on this series.

Regards, Anup

Thanks, Mark.

...

Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org

---

arch/arm/include/asm/kvm_host.h | 2 +- arch/arm/include/asm/kvm_psci.h | 4 ++ arch/arm/include/uapi/asm/kvm.h | 35 ++++++++++++++- arch/arm/kvm/arm.c | 1 + arch/arm/kvm/psci.c | 85 +++++++++++++++++++++++++++++++------ arch/arm64/include/asm/kvm_host.h | 2 +- arch/arm64/include/asm/kvm_psci.h | 4 ++ arch/arm64/include/uapi/asm/kvm.h | 35 ++++++++++++++- 8 files changed, 152 insertions(+), 16 deletions(-)

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index bce6d32..dc4e3ed 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -36,7 +36,7 @@ #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 #define KVM_HAVE_ONE_REG

-#define KVM_VCPU_MAX_FEATURES 1 +#define KVM_VCPU_MAX_FEATURES 2

#include <kvm/arm_vgic.h>

diff --git a/arch/arm/include/asm/kvm_psci.h b/arch/arm/include/asm/kvm_psci.h index 9a83d98..4c0e3e1 100644 --- a/arch/arm/include/asm/kvm_psci.h +++ b/arch/arm/include/asm/kvm_psci.h @@ -18,6 +18,10 @@ #ifndef __ARM_KVM_PSCI_H__ #define __ARM_KVM_PSCI_H__

+#define KVM_ARM_PSCI_0_1 1 +#define KVM_ARM_PSCI_0_2 2

+int kvm_psci_version(struct kvm_vcpu *vcpu); bool kvm_psci_call(struct kvm_vcpu *vcpu);

#endif /* __ARM_KVM_PSCI_H__ */ diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index c498b60..bf860e2 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -83,6 +83,7 @@ struct kvm_regs { #define KVM_VGIC_V2_CPU_SIZE 0x2000

#define KVM_ARM_VCPU_POWER_OFF 0 /* CPU is started in OFF state */ +#define KVM_ARM_VCPU_PSCI_0_2 1 /* CPU uses PSCI v0.2 */

struct kvm_vcpu_init { __u32 target; @@ -164,7 +165,7 @@ struct kvm_arch_memory_slot { /* Highest supported SPI, from VGIC_NR_IRQS */ #define KVM_ARM_IRQ_GIC_MAX 127

-/* PSCI interface */ +/* PSCI v0.1 interface */ #define KVM_PSCI_FN_BASE 0x95c1ba5e #define KVM_PSCI_FN(n) (KVM_PSCI_FN_BASE + (n))

@@ -173,9 +174,41 @@ struct kvm_arch_memory_slot { #define KVM_PSCI_FN_CPU_ON KVM_PSCI_FN(2) #define KVM_PSCI_FN_MIGRATE KVM_PSCI_FN(3)

+/* PSCI v0.2 interface */ +#define KVM_PSCI_0_2_FN_BASE 0x84000000 +#define KVM_PSCI_0_2_FN(n) (KVM_PSCI_0_2_FN_BASE + (n)) +#define KVM_PSCI_0_2_FN64_BASE 0xC4000000 +#define KVM_PSCI_0_2_FN64(n) (KVM_PSCI_0_2_FN64_BASE + (n))

+#define KVM_PSCI_0_2_FN_PSCI_VERSION KVM_PSCI_0_2_FN(0) +#define KVM_PSCI_0_2_FN_CPU_SUSPEND KVM_PSCI_0_2_FN(1) +#define KVM_PSCI_0_2_FN_CPU_OFF KVM_PSCI_0_2_FN(2) +#define KVM_PSCI_0_2_FN_CPU_ON KVM_PSCI_0_2_FN(3) +#define KVM_PSCI_0_2_FN_AFFINITY_INFO KVM_PSCI_0_2_FN(4) +#define KVM_PSCI_0_2_FN_MIGRATE KVM_PSCI_0_2_FN(5) +#define KVM_PSCI_0_2_FN_MIGRATE_INFO_TYPE \

•                                   KVM_PSCI_0_2_FN(6)
  

+#define KVM_PSCI_0_2_FN_MIGRATE_INFO_UP_CPU \

•                                   KVM_PSCI_0_2_FN(7)
  

+#define KVM_PSCI_0_2_FN_SYSTEM_OFF KVM_PSCI_0_2_FN(8) +#define KVM_PSCI_0_2_FN_SYSTEM_RESET KVM_PSCI_0_2_FN(9)

+#define KVM_PSCI_0_2_FN64_CPU_SUSPEND KVM_PSCI_0_2_FN64(1) +#define KVM_PSCI_0_2_FN64_CPU_ON KVM_PSCI_0_2_FN64(3) +#define KVM_PSCI_0_2_FN64_AFFINITY_INFO KVM_PSCI_0_2_FN64(4) +#define KVM_PSCI_0_2_FN64_MIGRATE KVM_PSCI_0_2_FN64(5) +#define KVM_PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU \

•                                   KVM_PSCI_0_2_FN64(7)
  

+/* PSCI return values */ #define KVM_PSCI_RET_SUCCESS 0 #define KVM_PSCI_RET_NI ((unsigned long)-1) #define KVM_PSCI_RET_INVAL ((unsigned long)-2) #define KVM_PSCI_RET_DENIED ((unsigned long)-3) +#define KVM_PSCI_RET_ALREADY_ON ((unsigned long)-4) +#define KVM_PSCI_RET_ON_PENDING ((unsigned long)-5) +#define KVM_PSCI_RET_INTERNAL_FAILURE ((unsigned long)-6) +#define KVM_PSCI_RET_NOT_PRESENT ((unsigned long)-7) +#define KVM_PSCI_RET_DISABLED ((unsigned long)-8)

#endif /* __ARM_KVM_H__ */ diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 151eb91..e508125 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -193,6 +193,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_DESTROY_MEMORY_REGION_WORKS: case KVM_CAP_ONE_REG: case KVM_CAP_ARM_PSCI:

•   case KVM_CAP_ARM_PSCI_0_2:
            r = 1;
            break;
    case KVM_CAP_COALESCED_MMIO:
  

diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 448f60e..7fdc881 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -85,17 +85,57 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) return KVM_PSCI_RET_SUCCESS; }

-/**

• • kvm_psci_call - handle PSCI call if r0 value is in range
• • @vcpu: Pointer to the VCPU struct
• • Handle PSCI calls from guests through traps from HVC instructions.
• • The calling convention is similar to SMC calls to the secure world where
• • the function number is placed in r0 and this function returns true if the
• • function number specified in r0 is withing the PSCI range, and false
• • otherwise.
• */

-bool kvm_psci_call(struct kvm_vcpu *vcpu) +int kvm_psci_version(struct kvm_vcpu *vcpu) +{

•   if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
  

•           return KVM_ARM_PSCI_0_2;
  

•   return KVM_ARM_PSCI_0_1;
  

+}

+static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu) +{

•   unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
  

•   unsigned long val;
  

•   switch (psci_fn) {
  

•   case KVM_PSCI_0_2_FN_PSCI_VERSION:
  

•           /*
  

•            * Bits[31:16] = Major Version = 0
  

•            * Bits[15:0] = Minor Version = 2
  

•            */
  

•           val = 2;
  

•           break;
  

•   case KVM_PSCI_0_2_FN_CPU_OFF:
  

•           kvm_psci_vcpu_off(vcpu);
  

•           val = KVM_PSCI_RET_SUCCESS;
  

•           break;
  

•   case KVM_PSCI_0_2_FN_CPU_ON:
  

•   case KVM_PSCI_0_2_FN64_CPU_ON:
  

•           val = kvm_psci_vcpu_on(vcpu);
  

•           break;
  

•   case KVM_PSCI_0_2_FN_CPU_SUSPEND:
  

•   case KVM_PSCI_0_2_FN_AFFINITY_INFO:
  

•   case KVM_PSCI_0_2_FN_MIGRATE:
  

•   case KVM_PSCI_0_2_FN_MIGRATE_INFO_TYPE:
  

•   case KVM_PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
  

•   case KVM_PSCI_0_2_FN_SYSTEM_OFF:
  

•   case KVM_PSCI_0_2_FN_SYSTEM_RESET:
  

•   case KVM_PSCI_0_2_FN64_CPU_SUSPEND:
  

•   case KVM_PSCI_0_2_FN64_AFFINITY_INFO:
  

•   case KVM_PSCI_0_2_FN64_MIGRATE:
  

•   case KVM_PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
  

•           val = KVM_PSCI_RET_NI;
  

•           break;
  

•   default:
  

•           return false;
  

•   }
  

•   *vcpu_reg(vcpu, 0) = val;
  

•   return true;
  

+}

+static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu) { unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); unsigned long val; @@ -112,7 +152,6 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu) case KVM_PSCI_FN_MIGRATE: val = KVM_PSCI_RET_NI; break;

•   default:
            return false;
    }
  

@@ -120,3 +159,25 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu) *vcpu_reg(vcpu, 0) = val; return true; }

+/**

• • kvm_psci_call - handle PSCI call if r0 value is in range
• • @vcpu: Pointer to the VCPU struct
• • Handle PSCI calls from guests through traps from HVC instructions.
• • The calling convention is similar to SMC calls to the secure world where
• • the function number is placed in r0 and this function returns true if the
• • function number specified in r0 is withing the PSCI range, and false
• • otherwise.
• */

+bool kvm_psci_call(struct kvm_vcpu *vcpu) +{

•   switch (kvm_psci_version(vcpu)) {
  

•   case KVM_ARM_PSCI_0_2:
  

•           return kvm_psci_0_2_call(vcpu);
  

•   case KVM_ARM_PSCI_0_1:
  

•           return kvm_psci_0_1_call(vcpu);
  

•   default:
  

•           return false;
  

•   };
  

+} diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 0a1d697..92242ce 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -39,7 +39,7 @@ #include <kvm/arm_vgic.h> #include <kvm/arm_arch_timer.h>

-#define KVM_VCPU_MAX_FEATURES 2 +#define KVM_VCPU_MAX_FEATURES 3

struct kvm_vcpu; int kvm_target_cpu(void); diff --git a/arch/arm64/include/asm/kvm_psci.h b/arch/arm64/include/asm/kvm_psci.h index e301a48..e25c658 100644 --- a/arch/arm64/include/asm/kvm_psci.h +++ b/arch/arm64/include/asm/kvm_psci.h @@ -18,6 +18,10 @@ #ifndef __ARM64_KVM_PSCI_H__ #define __ARM64_KVM_PSCI_H__

+#define KVM_ARM_PSCI_0_1 1 +#define KVM_ARM_PSCI_0_2 2

+int kvm_psci_version(struct kvm_vcpu *vcpu); bool kvm_psci_call(struct kvm_vcpu *vcpu);

#endif /* __ARM64_KVM_PSCI_H__ */ diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index d9f026b..b7555d3 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -77,6 +77,7 @@ struct kvm_regs {

#define KVM_ARM_VCPU_POWER_OFF 0 /* CPU is started in OFF state */ #define KVM_ARM_VCPU_EL1_32BIT 1 /* CPU running a 32bit VM */ +#define KVM_ARM_VCPU_PSCI_0_2 2 /* CPU uses PSCI v0.2 */

struct kvm_vcpu_init { __u32 target; @@ -150,7 +151,7 @@ struct kvm_arch_memory_slot { /* Highest supported SPI, from VGIC_NR_IRQS */ #define KVM_ARM_IRQ_GIC_MAX 127

-/* PSCI interface */ +/* PSCI v0.1 interface */ #define KVM_PSCI_FN_BASE 0x95c1ba5e #define KVM_PSCI_FN(n) (KVM_PSCI_FN_BASE + (n))

@@ -159,10 +160,42 @@ struct kvm_arch_memory_slot { #define KVM_PSCI_FN_CPU_ON KVM_PSCI_FN(2) #define KVM_PSCI_FN_MIGRATE KVM_PSCI_FN(3)

+/* PSCI v0.2 interface */ +#define KVM_PSCI_0_2_FN_BASE 0x84000000 +#define KVM_PSCI_0_2_FN(n) (KVM_PSCI_0_2_FN_BASE + (n)) +#define KVM_PSCI_0_2_FN64_BASE 0xC4000000 +#define KVM_PSCI_0_2_FN64(n) (KVM_PSCI_0_2_FN64_BASE + (n))

+#define KVM_PSCI_0_2_FN_PSCI_VERSION KVM_PSCI_0_2_FN(0) +#define KVM_PSCI_0_2_FN_CPU_SUSPEND KVM_PSCI_0_2_FN(1) +#define KVM_PSCI_0_2_FN_CPU_OFF KVM_PSCI_0_2_FN(2) +#define KVM_PSCI_0_2_FN_CPU_ON KVM_PSCI_0_2_FN(3) +#define KVM_PSCI_0_2_FN_AFFINITY_INFO KVM_PSCI_0_2_FN(4) +#define KVM_PSCI_0_2_FN_MIGRATE KVM_PSCI_0_2_FN(5) +#define KVM_PSCI_0_2_FN_MIGRATE_INFO_TYPE \

•                                   KVM_PSCI_0_2_FN(6)
  

+#define KVM_PSCI_0_2_FN_MIGRATE_INFO_UP_CPU \

•                                   KVM_PSCI_0_2_FN(7)
  

+#define KVM_PSCI_0_2_FN_SYSTEM_OFF KVM_PSCI_0_2_FN(8) +#define KVM_PSCI_0_2_FN_SYSTEM_RESET KVM_PSCI_0_2_FN(9)

+#define KVM_PSCI_0_2_FN64_CPU_SUSPEND KVM_PSCI_0_2_FN64(1) +#define KVM_PSCI_0_2_FN64_CPU_ON KVM_PSCI_0_2_FN64(3) +#define KVM_PSCI_0_2_FN64_AFFINITY_INFO KVM_PSCI_0_2_FN64(4) +#define KVM_PSCI_0_2_FN64_MIGRATE KVM_PSCI_0_2_FN64(5) +#define KVM_PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU \

•                                   KVM_PSCI_0_2_FN64(7)
  

+/* PSCI return values */ #define KVM_PSCI_RET_SUCCESS 0 #define KVM_PSCI_RET_NI ((unsigned long)-1) #define KVM_PSCI_RET_INVAL ((unsigned long)-2) #define KVM_PSCI_RET_DENIED ((unsigned long)-3) +#define KVM_PSCI_RET_ALREADY_ON ((unsigned long)-4) +#define KVM_PSCI_RET_ON_PENDING ((unsigned long)-5) +#define KVM_PSCI_RET_INTERNAL_FAILURE ((unsigned long)-6) +#define KVM_PSCI_RET_NOT_PRESENT ((unsigned long)-7) +#define KVM_PSCI_RET_DISABLED ((unsigned long)-8)

#endif

-- 1.7.9.5

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