Commit 42e35f80 authored by KarimAllah Ahmed's avatar KarimAllah Ahmed Committed by Paolo Bonzini
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KVM/X86: Use kvm_vcpu_map in emulator_cmpxchg_emulated 



Use kvm_vcpu_map in emulator_cmpxchg_emulated since using
kvm_vcpu_gpa_to_page() and kmap() will only work for guest memory that has
a "struct page".

Signed-off-by: default avatarKarimAllah Ahmed <karahmed@amazon.de>
Reviewed-by: default avatarKonrad Rzeszutek Wilk <kjonrad.wilk@oracle.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 3278e049

arch/x86/kvm/x86.c

+6 −8
Original line number Diff line number Diff line
@@ -5557,9 +5557,9 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt, 
				     unsigned int bytes,

				     struct x86_exception *exception)

{

	struct kvm_host_map map;

	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);

	gpa_t gpa;

	struct page *page;

	char *kaddr;

	bool exchanged;
@@ -5576,12 +5576,11 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt, 
	if (((gpa + bytes - 1) & PAGE_MASK) != (gpa & PAGE_MASK))

		goto emul_write;



	page = kvm_vcpu_gfn_to_page(vcpu, gpa >> PAGE_SHIFT);

	if (is_error_page(page))

	if (kvm_vcpu_map(vcpu, gpa_to_gfn(gpa), &map))

		goto emul_write;



	kaddr = kmap_atomic(page);

	kaddr += offset_in_page(gpa);

	kaddr = map.hva + offset_in_page(gpa);



	switch (bytes) {

	case 1:

		exchanged = CMPXCHG_TYPE(u8, kaddr, old, new);
@@ -5598,13 +5597,12 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt, 
	default:

		BUG();

	}

	kunmap_atomic(kaddr);

	kvm_release_page_dirty(page);



	kvm_vcpu_unmap(vcpu, &map, true);



	if (!exchanged)

		return X86EMUL_CMPXCHG_FAILED;



	kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);

	kvm_page_track_write(vcpu, gpa, new, bytes);



	return X86EMUL_CONTINUE;