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: KarimAllah Ahmed <karahmed@amazon.de>
Reviewed-by: Konrad Rzeszutek Wilk <kjonrad.wilk@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a7ea346fa41ed23009fbac131f451e125e959463..044ece3a28a44e6b1632434fac8be281482a17c4 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -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;