lkml.org 
[lkml]   [2022]   [Jan]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/2] KVM: x86: Use memcmp in kvm_cpuid_check_equal()
Date
kvm_cpuid_check_equal() should also check .flags equality but instead
of adding it to the existing check, just switch to using memcmp() for
the whole 'struct kvm_cpuid_entry2'.

When .flags are not checked, kvm_cpuid_check_equal() may allow an update
which it shouldn't but kvm_set_cpuid() does not actually update anything
and just returns success.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/cpuid.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 89d7822a8f5b..7dd9c8f4f46e 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -123,20 +123,11 @@ static int kvm_check_cpuid(struct kvm_vcpu *vcpu,
static int kvm_cpuid_check_equal(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2,
int nent)
{
- struct kvm_cpuid_entry2 *orig;
- int i;
-
if (nent != vcpu->arch.cpuid_nent)
return -EINVAL;

- for (i = 0; i < nent; i++) {
- orig = &vcpu->arch.cpuid_entries[i];
- if (e2[i].function != orig->function ||
- e2[i].index != orig->index ||
- e2[i].eax != orig->eax || e2[i].ebx != orig->ebx ||
- e2[i].ecx != orig->ecx || e2[i].edx != orig->edx)
- return -EINVAL;
- }
+ if (memcmp(e2, vcpu->arch.cpuid_entries, nent * sizeof(*e2)))
+ return -EINVAL;

return 0;
}
--
2.34.1
\
 
 \ /
  Last update: 2022-01-24 11:37    [W:0.085 / U:0.780 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site