lkml.org 
[lkml]   [2008]   [Sep]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 25/40] KVM: Ignore DEBUGCTL MSRs with no effect
Date
From: Alexander Graf <agraf@suse.de>

Netware writes to DEBUGCTL and reads from the DEBUGCTL and LAST*IP MSRs
without further checks and is really confused to receive a #GP during that.
To make it happy we should just make them stubs, which is exactly what SVM
already does.

Writes to DEBUGCTL that are vendor-specific are resembled to behave as if the
virtual CPU does not know them.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@qumranet.com>
---
arch/x86/kvm/x86.c | 17 +++++++++++++++++
1 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5620df2..94a2165 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -665,6 +665,18 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
pr_unimpl(vcpu, "%s: MSR_IA32_MCG_CTL 0x%llx, nop\n",
__func__, data);
break;
+ case MSR_IA32_DEBUGCTLMSR:
+ if (!data) {
+ /* We support the non-activated case already */
+ break;
+ } else if (data & ~(DEBUGCTLMSR_LBR | DEBUGCTLMSR_BTF)) {
+ /* Values other than LBR and BTF are vendor-specific,
+ thus reserved and should throw a #GP */
+ return 1;
+ }
+ pr_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n",
+ __func__, data);
+ break;
case MSR_IA32_UCODE_REV:
case MSR_IA32_UCODE_WRITE:
break;
@@ -757,6 +769,11 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
case MSR_IA32_MC0_MISC+16:
case MSR_IA32_UCODE_REV:
case MSR_IA32_EBL_CR_POWERON:
+ case MSR_IA32_DEBUGCTLMSR:
+ case MSR_IA32_LASTBRANCHFROMIP:
+ case MSR_IA32_LASTBRANCHTOIP:
+ case MSR_IA32_LASTINTFROMIP:
+ case MSR_IA32_LASTINTTOIP:
data = 0;
break;
case MSR_MTRRcap:
--
1.6.0.1


\
 
 \ /
  Last update: 2008-09-23 16:03    [W:0.170 / U:14.040 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site