From: Marcelo Tosatti <mtosatti@redhat.com>
To: Andy Honig <ahonig@google.com>, Gleb Natapov <gleb@redhat.com>
Cc: kvm <kvm@vger.kernel.org>
Subject: KVM: x86: relax MSR_KVM_SYSTEM_TIME alignment check
Date: Fri, 22 Mar 2013 16:14:07 -0300 [thread overview]
Message-ID: <20130322191407.GA23681@amt.cnet> (raw)
RHEL5 i386 guests register non 32-byte aligned addresses:
kvm-clock: cpu 1, msr 0:3018aa5, secondary cpu clock
kvm-clock: cpu 2, msr 0:301f8e9, secondary cpu clock
kvm-clock: cpu 3, msr 0:302672d, secondary cpu clock
Check for an address+len that would cross page boundary
instead.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f19ac0a..ad36d386 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1952,8 +1952,9 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
gpa_offset = data & ~(PAGE_MASK | 1);
- /* Check that the address is 32-byte aligned. */
- if (gpa_offset & (sizeof(struct pvclock_vcpu_time_info) - 1))
+ /* Check that address+len does not cross page boundary */
+ if ((gpa_offset + sizeof(struct pvclock_vcpu_time_info) - 1)
+ & PAGE_MASK)
break;
if (kvm_gfn_to_hva_cache_init(vcpu->kvm,
next reply other threads:[~2013-03-22 19:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-22 19:14 Marcelo Tosatti [this message]
2013-03-22 19:21 ` KVM: x86: relax MSR_KVM_SYSTEM_TIME alignment check Gleb Natapov
2013-03-22 19:47 ` Marcelo Tosatti
2013-03-22 21:19 ` KVM: x86: drop alignment checks from KVM_MSR_SYSTEM_TIME address Marcelo Tosatti
2013-03-22 21:57 ` Gleb Natapov
2013-03-23 0:17 ` Andrew Honig
2013-03-23 14:12 ` Gleb Natapov
2013-04-11 16:05 ` Marcelo Tosatti
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