KVM: vmx: print more APICv fields in dump_vmcs
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Message ID 1555335333-23636-1-git-send-email-pbonzini@redhat.com
State New
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Series
  • KVM: vmx: print more APICv fields in dump_vmcs
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Commit Message

Paolo Bonzini April 15, 2019, 1:35 p.m. UTC
The SVI, RVI, virtual-APIC page address and APIC-access page address fields
were left out of dump_vmcs.  Add them.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/vmx.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

Comments

Sean Christopherson April 15, 2019, 6:39 p.m. UTC | #1
On Mon, Apr 15, 2019 at 03:35:32PM +0200, Paolo Bonzini wrote:
> The SVI, RVI, virtual-APIC page address and APIC-access page address fields
> were left out of dump_vmcs.  Add them.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  arch/x86/kvm/vmx/vmx.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index ab432a930ae8..f8054dc1de65 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -5723,8 +5723,17 @@ static void dump_vmcs(void)
>  	if (secondary_exec_control & SECONDARY_EXEC_TSC_SCALING)
>  		pr_err("TSC Multiplier = 0x%016llx\n",
>  		       vmcs_read64(TSC_MULTIPLIER));
> -	if (cpu_based_exec_ctrl & CPU_BASED_TPR_SHADOW)
> -		pr_err("TPR Threshold = 0x%02x\n", vmcs_read32(TPR_THRESHOLD));
> +	if (cpu_based_exec_ctrl & CPU_BASED_TPR_SHADOW) {
> +		if (secondary_exec_control & SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY) {
> +			u16 status = vmcs_read16(GUEST_INTR_STATUS);
> +			pr_err("SVI|RVI = %02x|%02x ", status >> 8, status & 0xff);
> +		}
> +		pr_err(KERN_CONT "TPR Threshold = 0x%02x\n", vmcs_read32(TPR_THRESHOLD));

Might be worth adding a blurb in the changelog stating it's ok to use
KERN_CONT even though it's technically not SMP safe, as the whole
dump_vmcs() flow isn't exactly SMP safe.

> +		if (secondary_exec_control & (SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
> +		    			      SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE))

Do we really want to dump the APIC access page address for x2APIC?  I
assume your intent is to show the value that *could* be used if the guest
were to disable x2APIC, but that might be misleading since APIC_ACCESS_ADDR
is checked if and only if VIRTUALIZE_APIC_ACCESSES=1, e.g. someone might
think a VM-Enter failed because APIC_ACCESS_ADDR has a "bad" value even
though it's ignored.

> +			pr_err("APIC-access addr = 0x%016llx ", vmcs_read64(APIC_ACCESS_ADDR));
> +		pr_err(KERN_CONT "virt-APIC addr=0x%016llx\n", vmcs_read64(VIRTUAL_APIC_PAGE_ADDR));
> +	}
>  	if (pin_based_exec_ctrl & PIN_BASED_POSTED_INTR)
>  		pr_err("PostedIntrVec = 0x%02x\n", vmcs_read16(POSTED_INTR_NV));
>  	if ((secondary_exec_control & SECONDARY_EXEC_ENABLE_EPT))
> -- 
> 1.8.3.1
>
Paolo Bonzini April 16, 2019, 9:08 a.m. UTC | #2
On 15/04/19 20:39, Sean Christopherson wrote:
> On Mon, Apr 15, 2019 at 03:35:32PM +0200, Paolo Bonzini wrote:
>> The SVI, RVI, virtual-APIC page address and APIC-access page address fields
>> were left out of dump_vmcs.  Add them.
>>
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>> ---
>>  arch/x86/kvm/vmx/vmx.c | 13 +++++++++++--
>>  1 file changed, 11 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
>> index ab432a930ae8..f8054dc1de65 100644
>> --- a/arch/x86/kvm/vmx/vmx.c
>> +++ b/arch/x86/kvm/vmx/vmx.c
>> @@ -5723,8 +5723,17 @@ static void dump_vmcs(void)
>>  	if (secondary_exec_control & SECONDARY_EXEC_TSC_SCALING)
>>  		pr_err("TSC Multiplier = 0x%016llx\n",
>>  		       vmcs_read64(TSC_MULTIPLIER));
>> -	if (cpu_based_exec_ctrl & CPU_BASED_TPR_SHADOW)
>> -		pr_err("TPR Threshold = 0x%02x\n", vmcs_read32(TPR_THRESHOLD));
>> +	if (cpu_based_exec_ctrl & CPU_BASED_TPR_SHADOW) {
>> +		if (secondary_exec_control & SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY) {
>> +			u16 status = vmcs_read16(GUEST_INTR_STATUS);
>> +			pr_err("SVI|RVI = %02x|%02x ", status >> 8, status & 0xff);
>> +		}
>> +		pr_err(KERN_CONT "TPR Threshold = 0x%02x\n", vmcs_read32(TPR_THRESHOLD));
> 
> Might be worth adding a blurb in the changelog stating it's ok to use
> KERN_CONT even though it's technically not SMP safe, as the whole
> dump_vmcs() flow isn't exactly SMP safe.
> 
>> +		if (secondary_exec_control & (SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
>> +		    			      SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE))
> 
> Do we really want to dump the APIC access page address for x2APIC?  I
> assume your intent is to show the value that *could* be used if the guest
> were to disable x2APIC, but that might be misleading since APIC_ACCESS_ADDR
> is checked if and only if VIRTUALIZE_APIC_ACCESSES=1, e.g. someone might
> think a VM-Enter failed because APIC_ACCESS_ADDR has a "bad" value even
> though it's ignored.

Indeed, brain fart.  It's the virtual-APIC page that matters for virtual
x2APIC mode, and that one indeed is printed below (because virtual
x2APIC requires TPR shadow).

Paolo
Krish Sadhukhan April 17, 2019, 12:36 a.m. UTC | #3
On 04/15/2019 06:35 AM, Paolo Bonzini wrote:
> The SVI, RVI, virtual-APIC page address and APIC-access page address fields
> were left out of dump_vmcs.  Add them.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>   arch/x86/kvm/vmx/vmx.c | 13 +++++++++++--
>   1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index ab432a930ae8..f8054dc1de65 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -5723,8 +5723,17 @@ static void dump_vmcs(void)
>   	if (secondary_exec_control & SECONDARY_EXEC_TSC_SCALING)
>   		pr_err("TSC Multiplier = 0x%016llx\n",
>   		       vmcs_read64(TSC_MULTIPLIER));
> -	if (cpu_based_exec_ctrl & CPU_BASED_TPR_SHADOW)
> -		pr_err("TPR Threshold = 0x%02x\n", vmcs_read32(TPR_THRESHOLD));
> +	if (cpu_based_exec_ctrl & CPU_BASED_TPR_SHADOW) {
> +		if (secondary_exec_control & SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY) {
> +			u16 status = vmcs_read16(GUEST_INTR_STATUS);
> +			pr_err("SVI|RVI = %02x|%02x ", status >> 8, status & 0xff);
> +		}
> +		pr_err(KERN_CONT "TPR Threshold = 0x%02x\n", vmcs_read32(TPR_THRESHOLD));
> +		if (secondary_exec_control & (SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
> +		    			      SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE))
> +			pr_err("APIC-access addr = 0x%016llx ", vmcs_read64(APIC_ACCESS_ADDR));
> +		pr_err(KERN_CONT "virt-APIC addr=0x%016llx\n", vmcs_read64(VIRTUAL_APIC_PAGE_ADDR));
> +	}
>   	if (pin_based_exec_ctrl & PIN_BASED_POSTED_INTR)
>   		pr_err("PostedIntrVec = 0x%02x\n", vmcs_read16(POSTED_INTR_NV));
>   	if ((secondary_exec_control & SECONDARY_EXEC_ENABLE_EPT))

Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>

Patch
diff mbox series

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ab432a930ae8..f8054dc1de65 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5723,8 +5723,17 @@  static void dump_vmcs(void)
 	if (secondary_exec_control & SECONDARY_EXEC_TSC_SCALING)
 		pr_err("TSC Multiplier = 0x%016llx\n",
 		       vmcs_read64(TSC_MULTIPLIER));
-	if (cpu_based_exec_ctrl & CPU_BASED_TPR_SHADOW)
-		pr_err("TPR Threshold = 0x%02x\n", vmcs_read32(TPR_THRESHOLD));
+	if (cpu_based_exec_ctrl & CPU_BASED_TPR_SHADOW) {
+		if (secondary_exec_control & SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY) {
+			u16 status = vmcs_read16(GUEST_INTR_STATUS);
+			pr_err("SVI|RVI = %02x|%02x ", status >> 8, status & 0xff);
+		}
+		pr_err(KERN_CONT "TPR Threshold = 0x%02x\n", vmcs_read32(TPR_THRESHOLD));
+		if (secondary_exec_control & (SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
+		    			      SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE))
+			pr_err("APIC-access addr = 0x%016llx ", vmcs_read64(APIC_ACCESS_ADDR));
+		pr_err(KERN_CONT "virt-APIC addr=0x%016llx\n", vmcs_read64(VIRTUAL_APIC_PAGE_ADDR));
+	}
 	if (pin_based_exec_ctrl & PIN_BASED_POSTED_INTR)
 		pr_err("PostedIntrVec = 0x%02x\n", vmcs_read16(POSTED_INTR_NV));
 	if ((secondary_exec_control & SECONDARY_EXEC_ENABLE_EPT))