Re: [PATCH v2 23/23] [HACK] xen/arm: implement xen_remap_domain_mfn_range

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