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authorKai Huang <kai.huang@linux.intel.com>2015-11-04 06:46:05 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2015-11-05 11:34:11 +0100
commita3eaa8649e4c6a6afdafaa04b9114fb230617bb1 (patch)
tree878f0e28bd9734f3c7c822771d9f501f7880b707
parentKVM: x86: obey KVM_X86_QUIRK_CD_NW_CLEARED in kvm_set_cr0() (diff)
downloadlinux-a3eaa8649e4c6a6afdafaa04b9114fb230617bb1.tar.xz
linux-a3eaa8649e4c6a6afdafaa04b9114fb230617bb1.zip
KVM: VMX: Fix commit which broke PML
I found PML was broken since below commit: commit feda805fe7c4ed9cf78158e73b1218752e3b4314 Author: Xiao Guangrong <guangrong.xiao@linux.intel.com> Date: Wed Sep 9 14:05:55 2015 +0800 KVM: VMX: unify SECONDARY_VM_EXEC_CONTROL update Unify the update in vmx_cpuid_update() Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> [Rewrite to use vmcs_set_secondary_exec_control. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> The reason is in above commit vmx_cpuid_update calls vmx_secondary_exec_control, in which currently SECONDARY_EXEC_ENABLE_PML bit is cleared unconditionally (as PML is enabled in creating vcpu). Therefore if vcpu_cpuid_update is called after vcpu is created, PML will be disabled unexpectedly while log-dirty code still thinks PML is used. Fix this by clearing SECONDARY_EXEC_ENABLE_PML in vmx_secondary_exec_control only when PML is not supported or not enabled (!enable_pml). This is more reasonable as PML is currently either always enabled or disabled. With this explicit updating SECONDARY_EXEC_ENABLE_PML in vmx_enable{disable}_pml is not needed so also rename vmx_enable{disable}_pml to vmx_create{destroy}_pml_buffer. Fixes: feda805fe7c4ed9cf78158e73b1218752e3b4314 Signed-off-by: Kai Huang <kai.huang@linux.intel.com> [While at it, change a wrong ASSERT to an "if". The condition can happen if creating the VCPU fails with ENOMEM. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/vmx.c24
1 files changed, 11 insertions, 13 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 2ac116417583..5eb56ed77c1f 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4718,8 +4718,9 @@ static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx)
a current VMCS12
*/
exec_control &= ~SECONDARY_EXEC_SHADOW_VMCS;
- /* PML is enabled/disabled in creating/destorying vcpu */
- exec_control &= ~SECONDARY_EXEC_ENABLE_PML;
+
+ if (!enable_pml)
+ exec_control &= ~SECONDARY_EXEC_ENABLE_PML;
/* Currently, we allow L1 guest to directly run pcommit instruction. */
exec_control &= ~SECONDARY_EXEC_PCOMMIT;
@@ -7804,7 +7805,7 @@ static void vmx_get_exit_info(struct kvm_vcpu *vcpu, u64 *info1, u64 *info2)
*info2 = vmcs_read32(VM_EXIT_INTR_INFO);
}
-static int vmx_enable_pml(struct vcpu_vmx *vmx)
+static int vmx_create_pml_buffer(struct vcpu_vmx *vmx)
{
struct page *pml_pg;
@@ -7817,18 +7818,15 @@ static int vmx_enable_pml(struct vcpu_vmx *vmx)
vmcs_write64(PML_ADDRESS, page_to_phys(vmx->pml_pg));
vmcs_write16(GUEST_PML_INDEX, PML_ENTITY_NUM - 1);
- vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL, SECONDARY_EXEC_ENABLE_PML);
-
return 0;
}
-static void vmx_disable_pml(struct vcpu_vmx *vmx)
+static void vmx_destroy_pml_buffer(struct vcpu_vmx *vmx)
{
- ASSERT(vmx->pml_pg);
- __free_page(vmx->pml_pg);
- vmx->pml_pg = NULL;
-
- vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL, SECONDARY_EXEC_ENABLE_PML);
+ if (vmx->pml_pg) {
+ __free_page(vmx->pml_pg);
+ vmx->pml_pg = NULL;
+ }
}
static void vmx_flush_pml_buffer(struct kvm_vcpu *vcpu)
@@ -8706,7 +8704,7 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu)
struct vcpu_vmx *vmx = to_vmx(vcpu);
if (enable_pml)
- vmx_disable_pml(vmx);
+ vmx_destroy_pml_buffer(vmx);
free_vpid(vmx->vpid);
leave_guest_mode(vcpu);
vmx_load_vmcs01(vcpu);
@@ -8790,7 +8788,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
* for the guest, etc.
*/
if (enable_pml) {
- err = vmx_enable_pml(vmx);
+ err = vmx_create_pml_buffer(vmx);
if (err)
goto free_vmcs;
}