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KVM: VMX: Fix commit which broke PML

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I found PML was broken since below commit:

	commit feda805fe7
	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: feda805fe7
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>
This commit is contained in:
Kai Huang
2015-11-04 13:46:05 +08:00
committed by Paolo Bonzini
parent 879ae18804
commit a3eaa8649e
1 changed files with 11 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files
arch/x86/kvm/vmx.c
+11 -13
View File
@@ -4718,8 +4718,9 @@ static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx)
a current VMCS12 a current VMCS12
*/ */
exec_control &= ~SECONDARY_EXEC_SHADOW_VMCS; 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. */ /* Currently, we allow L1 guest to directly run pcommit instruction. */
exec_control &= ~SECONDARY_EXEC_PCOMMIT; 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); *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; 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_write64(PML_ADDRESS, page_to_phys(vmx->pml_pg));
vmcs_write16(GUEST_PML_INDEX, PML_ENTITY_NUM - 1); vmcs_write16(GUEST_PML_INDEX, PML_ENTITY_NUM - 1);
vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL, SECONDARY_EXEC_ENABLE_PML);
return 0; 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); if (vmx->pml_pg) {
__free_page(vmx->pml_pg); __free_page(vmx->pml_pg);
vmx->pml_pg = NULL; vmx->pml_pg = NULL;
}
vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL, SECONDARY_EXEC_ENABLE_PML);
} }
static void vmx_flush_pml_buffer(struct kvm_vcpu *vcpu) 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); struct vcpu_vmx *vmx = to_vmx(vcpu);
if (enable_pml) if (enable_pml)
vmx_disable_pml(vmx); vmx_destroy_pml_buffer(vmx);
free_vpid(vmx->vpid); free_vpid(vmx->vpid);
leave_guest_mode(vcpu); leave_guest_mode(vcpu);
vmx_load_vmcs01(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. * for the guest, etc.
*/ */
if (enable_pml) { if (enable_pml) {
err = vmx_enable_pml(vmx); err = vmx_create_pml_buffer(vmx);
if (err) if (err)
goto free_vmcs; goto free_vmcs;
} }