[PATCH v3 09/13] KVM/X86: Use kvm_vcpu_map in emulator_cmpxchg_emulated

[KarimAllah Ahmed]

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 <karah...@amazon.de>
---
v1 -> v2:
- Update to match the new API return codes
---
 arch/x86/kvm/x86.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ca71773..f083e53 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5280,9 +5280,9 @@ 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;
 
@@ -5299,12 +5299,11 @@ 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);
@@ -5321,8 +5320,8 @@ static int emulator_cmpxchg_emulated(struct 
x86_emulate_ctxt *ctxt,
        default:
                BUG();
        }
-       kunmap_atomic(kaddr);
-       kvm_release_page_dirty(page);
+
+       kvm_vcpu_unmap(&map);
 
        if (!exchanged)
                return X86EMUL_CMPXCHG_FAILED;
-- 
2.7.4