[RFC 09/12] KVM/VMX: Use the new host mapping API for cmpxchg_emulated

From: KarimAllah Ahmed
Date: Mon Feb 05 2018 - 13:49:00 EST


Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: KarimAllah Ahmed <karahmed@xxxxxxxxx>
---
arch/x86/kvm/x86.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ac38143..db0fd24 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4843,9 +4843,9 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
unsigned int bytes,
struct x86_exception *exception)
{
+ struct kvm_host_mapping mapping;
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
gpa_t gpa;
- struct page *page;
char *kaddr;
bool exchanged;

@@ -4862,12 +4862,10 @@ 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_gpa_to_host_mapping(vcpu, gpa, &mapping, true))
goto emul_write;

- kaddr = kmap_atomic(page);
- kaddr += offset_in_page(gpa);
+ kaddr = mapping.kaddr + offset_in_page(gpa);
switch (bytes) {
case 1:
exchanged = CMPXCHG_TYPE(u8, kaddr, old, new);
@@ -4884,8 +4882,8 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
default:
BUG();
}
- kunmap_atomic(kaddr);
- kvm_release_page_dirty(page);
+
+ kvm_release_host_mapping(&mapping, true);

if (!exchanged)
return X86EMUL_CMPXCHG_FAILED;
--
2.7.4