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authorJan Kiszka <jan.kiszka@siemens.com>2014-06-30 10:54:17 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2014-07-09 18:09:55 +0200
commit9bf418335e24da995ea682a028926d7e1036be6f (patch)
tree2744a9564a101286b60272ff7eff4c216326d19c /arch/x86/kvm/svm.c
parent62baf44cad3bc6b37115cc21e4228fe53d4f3474 (diff)
downloadop-kernel-dev-9bf418335e24da995ea682a028926d7e1036be6f.zip
op-kernel-dev-9bf418335e24da995ea682a028926d7e1036be6f.tar.gz
KVM: nSVM: Fix IOIO bitmap evaluation
First, kvm_read_guest returns 0 on success. And then we need to take the access size into account when testing the bitmap: intercept if any of bits corresponding to the access is set. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm.c')
-rw-r--r--arch/x86/kvm/svm.c19
1 files changed, 12 insertions, 7 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index c79766e1..3483ac9 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2116,22 +2116,27 @@ static void nested_svm_unmap(struct page *page)
static int nested_svm_intercept_ioio(struct vcpu_svm *svm)
{
- unsigned port;
- u8 val, bit;
+ unsigned port, size, iopm_len;
+ u16 val, mask;
+ u8 start_bit;
u64 gpa;
if (!(svm->nested.intercept & (1ULL << INTERCEPT_IOIO_PROT)))
return NESTED_EXIT_HOST;
port = svm->vmcb->control.exit_info_1 >> 16;
+ size = (svm->vmcb->control.exit_info_1 & SVM_IOIO_SIZE_MASK) >>
+ SVM_IOIO_SIZE_SHIFT;
gpa = svm->nested.vmcb_iopm + (port / 8);
- bit = port % 8;
- val = 0;
+ start_bit = port % 8;
+ iopm_len = (start_bit + size > 8) ? 2 : 1;
+ mask = (0xf >> (4 - size)) << start_bit;
+ val = 0;
- if (kvm_read_guest(svm->vcpu.kvm, gpa, &val, 1))
- val &= (1 << bit);
+ if (kvm_read_guest(svm->vcpu.kvm, gpa, &val, iopm_len))
+ return NESTED_EXIT_DONE;
- return val ? NESTED_EXIT_DONE : NESTED_EXIT_HOST;
+ return (val & mask) ? NESTED_EXIT_DONE : NESTED_EXIT_HOST;
}
static int nested_svm_exit_handled_msr(struct vcpu_svm *svm)
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