xen: privcmd: support autotranslated physmap guests. (d71f5139) · Commits · 戴 / test

drivers/xen/privcmd.c

+67 −2

Original line number	Diff line number	Diff line
		@@ -33,11 +33,14 @@
		#include <xen/features.h>
		#include <xen/page.h>
		#include <xen/xen-ops.h>
		#include <xen/balloon.h>

		#include "privcmd.h"

		MODULE_LICENSE("GPL");

		#define PRIV_VMA_LOCKED ((void *)1)

		#ifndef HAVE_ARCH_PRIVCMD_MMAP
		static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma);
		#endif
		@@ -199,6 +202,10 @@ static long privcmd_ioctl_mmap(void __user *udata)
		if (!xen_initial_domain())
		return -EPERM;

		/* We only support privcmd_ioctl_mmap_batch for auto translated. */
		if (xen_feature(XENFEAT_auto_translated_physmap))
		return -ENOSYS;

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

		@@ -246,6 +253,7 @@ struct mmap_batch_state {
		domid_t domain;
		unsigned long va;
		struct vm_area_struct *vma;
		int index;
		/* A tristate:
		* 0 for no errors
		* 1 if at least one error has happened (and no
		@@ -260,15 +268,24 @@ struct mmap_batch_state {
		xen_pfn_t __user *user_mfn;
		};

		/* auto translated dom0 note: if domU being created is PV, then mfn is
		* mfn(addr on bus). If it's auto xlated, then mfn is pfn (input to HAP).
		*/
		static int mmap_batch_fn(void data, void state)
		{
		xen_pfn_t *mfnp = data;
		struct mmap_batch_state *st = state;
		struct vm_area_struct *vma = st->vma;
		struct page **pages = vma->vm_private_data;
		struct page *cur_page = NULL;
		int ret;

		if (xen_feature(XENFEAT_auto_translated_physmap))
		cur_page = pages[st->index++];

		ret = xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
		st->vma->vm_page_prot, st->domain,
		NULL);
		&cur_page);

		/* Store error code for second pass. */
		*(st->err++) = ret;
		@@ -304,6 +321,32 @@ static int mmap_return_errors_v1(void data, void state)
		return __put_user(*mfnp, st->user_mfn++);
		}

		/* Allocate pfns that are then mapped with gmfns from foreign domid. Update
		* the vma with the page info to use later.
		* Returns: 0 if success, otherwise -errno
		*/
		static int alloc_empty_pages(struct vm_area_struct *vma, int numpgs)
		{
		int rc;
		struct page **pages;

		pages = kcalloc(numpgs, sizeof(pages[0]), GFP_KERNEL);
		if (pages == NULL)
		return -ENOMEM;

		rc = alloc_xenballooned_pages(numpgs, pages, 0);
		if (rc != 0) {
		pr_warn("%s Could not alloc %d pfns rc:%d\n", __func__,
		numpgs, rc);
		kfree(pages);
		return -ENOMEM;
		}
		BUG_ON(vma->vm_private_data != PRIV_VMA_LOCKED);
		vma->vm_private_data = pages;

		return 0;
		}

		static struct vm_operations_struct privcmd_vm_ops;

		static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
		@@ -371,10 +414,18 @@ static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
		up_write(&mm->mmap_sem);
		goto out;
		}
		if (xen_feature(XENFEAT_auto_translated_physmap)) {
		ret = alloc_empty_pages(vma, m.num);
		if (ret < 0) {
		up_write(&mm->mmap_sem);
		goto out;
		}
		}

		state.domain = m.dom;
		state.vma = vma;
		state.va = m.addr;
		state.index = 0;
		state.global_error = 0;
		state.err = err_array;

		@@ -439,6 +490,19 @@ static long privcmd_ioctl(struct file *file,
		return ret;
		}

		static void privcmd_close(struct vm_area_struct *vma)
		{
		struct page **pages = vma->vm_private_data;
		int numpgs = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;

		if (!xen_feature(XENFEAT_auto_translated_physmap \|\| !numpgs \|\| !pages))
		return;

		xen_unmap_domain_mfn_range(vma, numpgs, pages);
		free_xenballooned_pages(numpgs, pages);
		kfree(pages);
		}

		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",
		@@ -449,6 +513,7 @@ static int privcmd_fault(struct vm_area_struct vma, struct vm_fault vmf)
		}

		static struct vm_operations_struct privcmd_vm_ops = {
		.close = privcmd_close,
		.fault = privcmd_fault
		};

		@@ -466,7 +531,7 @@ static int privcmd_mmap(struct file file, struct vm_area_struct vma)

		static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma)
		{
		return (xchg(&vma->vm_private_data, (void *)1) == NULL);
		return !cmpxchg(&vma->vm_private_data, NULL, PRIV_VMA_LOCKED);
		}

		const struct file_operations xen_privcmd_fops = {

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