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Commit 8c23f406 authored by Linus Torvalds's avatar Linus Torvalds
Browse files
Pull KVM fix from Marcelo Tosatti.

* git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: fix vcpu->mmio_fragments overflow
parents 1e207eb1 87da7e66
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+34 −26
Original line number Diff line number Diff line
@@ -3779,7 +3779,7 @@ static int write_exit_mmio(struct kvm_vcpu *vcpu, gpa_t gpa,
{
	struct kvm_mmio_fragment *frag = &vcpu->mmio_fragments[0];

	memcpy(vcpu->run->mmio.data, frag->data, frag->len);
	memcpy(vcpu->run->mmio.data, frag->data, min(8u, frag->len));
	return X86EMUL_CONTINUE;
}

@@ -3832,18 +3832,11 @@ static int emulator_read_write_onepage(unsigned long addr, void *val,
	bytes -= handled;
	val += handled;

	while (bytes) {
		unsigned now = min(bytes, 8U);

	WARN_ON(vcpu->mmio_nr_fragments >= KVM_MAX_MMIO_FRAGMENTS);
	frag = &vcpu->mmio_fragments[vcpu->mmio_nr_fragments++];
	frag->gpa = gpa;
	frag->data = val;
		frag->len = now;

		gpa += now;
		val += now;
		bytes -= now;
	}
	frag->len = bytes;
	return X86EMUL_CONTINUE;
}

@@ -3890,7 +3883,7 @@ int emulator_read_write(struct x86_emulate_ctxt *ctxt, unsigned long addr,
	vcpu->mmio_needed = 1;
	vcpu->mmio_cur_fragment = 0;

	vcpu->run->mmio.len = vcpu->mmio_fragments[0].len;
	vcpu->run->mmio.len = min(8u, vcpu->mmio_fragments[0].len);
	vcpu->run->mmio.is_write = vcpu->mmio_is_write = ops->write;
	vcpu->run->exit_reason = KVM_EXIT_MMIO;
	vcpu->run->mmio.phys_addr = gpa;
@@ -5522,6 +5515,7 @@ static int complete_emulated_pio(struct kvm_vcpu *vcpu)
 *
 * read:
 *   for each fragment
 *     for each mmio piece in the fragment
 *       write gpa, len
 *       exit
 *       copy data
@@ -5529,6 +5523,7 @@ static int complete_emulated_pio(struct kvm_vcpu *vcpu)
 *
 * write:
 *   for each fragment
 *     for each mmio piece in the fragment
 *       write gpa, len
 *       copy data
 *       exit
@@ -5537,13 +5532,27 @@ static int complete_emulated_mmio(struct kvm_vcpu *vcpu)
{
	struct kvm_run *run = vcpu->run;
	struct kvm_mmio_fragment *frag;
	unsigned len;

	BUG_ON(!vcpu->mmio_needed);

	/* Complete previous fragment */
	frag = &vcpu->mmio_fragments[vcpu->mmio_cur_fragment++];
	frag = &vcpu->mmio_fragments[vcpu->mmio_cur_fragment];
	len = min(8u, frag->len);
	if (!vcpu->mmio_is_write)
		memcpy(frag->data, run->mmio.data, frag->len);
		memcpy(frag->data, run->mmio.data, len);

	if (frag->len <= 8) {
		/* Switch to the next fragment. */
		frag++;
		vcpu->mmio_cur_fragment++;
	} else {
		/* Go forward to the next mmio piece. */
		frag->data += len;
		frag->gpa += len;
		frag->len -= len;
	}

	if (vcpu->mmio_cur_fragment == vcpu->mmio_nr_fragments) {
		vcpu->mmio_needed = 0;
		if (vcpu->mmio_is_write)
@@ -5551,13 +5560,12 @@ static int complete_emulated_mmio(struct kvm_vcpu *vcpu)
		vcpu->mmio_read_completed = 1;
		return complete_emulated_io(vcpu);
	}
	/* Initiate next fragment */
	++frag;

	run->exit_reason = KVM_EXIT_MMIO;
	run->mmio.phys_addr = frag->gpa;
	if (vcpu->mmio_is_write)
		memcpy(run->mmio.data, frag->data, frag->len);
	run->mmio.len = frag->len;
		memcpy(run->mmio.data, frag->data, min(8u, frag->len));
	run->mmio.len = min(8u, frag->len);
	run->mmio.is_write = vcpu->mmio_is_write;
	vcpu->arch.complete_userspace_io = complete_emulated_mmio;
	return 0;
+2 −13
Original line number Diff line number Diff line
@@ -42,19 +42,8 @@
 */
#define KVM_MEMSLOT_INVALID	(1UL << 16)

/*
 * If we support unaligned MMIO, at most one fragment will be split into two:
 */
#ifdef KVM_UNALIGNED_MMIO
#  define KVM_EXTRA_MMIO_FRAGMENTS 1
#else
#  define KVM_EXTRA_MMIO_FRAGMENTS 0
#endif

#define KVM_USER_MMIO_SIZE 8

#define KVM_MAX_MMIO_FRAGMENTS \
	(KVM_MMIO_SIZE / KVM_USER_MMIO_SIZE + KVM_EXTRA_MMIO_FRAGMENTS)
/* Two fragments for cross MMIO pages. */
#define KVM_MAX_MMIO_FRAGMENTS	2

/*
 * For the normal pfn, the highest 12 bits should be zero,