diff mbox series

[v2,2/3] KVM: x86: dump_vmcs should not conflate EFER and PAT presence in VMCS

Message ID 20210219144632.2288189-3-david.edmondson@oracle.com (mailing list archive)
State New, archived
Headers show
Series KVM: x86: dump_vmcs: don't assume GUEST_IA32_EFER, show MSR autoloads/autosaves | expand

Commit Message

David Edmondson Feb. 19, 2021, 2:46 p.m. UTC
Show EFER and PAT based on their individual entry/exit controls.

Signed-off-by: David Edmondson <david.edmondson@oracle.com>
---
 arch/x86/kvm/vmx/vmx.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

Comments

Sean Christopherson Feb. 23, 2021, 10:58 p.m. UTC | #1
On Fri, Feb 19, 2021, David Edmondson wrote:
> Show EFER and PAT based on their individual entry/exit controls.
> 
> Signed-off-by: David Edmondson <david.edmondson@oracle.com>
> ---
>  arch/x86/kvm/vmx/vmx.c | 19 ++++++++++---------
>  1 file changed, 10 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 818051c9fa10..25090e3683ca 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -5805,11 +5805,12 @@ void dump_vmcs(void)
>  	vmx_dump_sel("LDTR:", GUEST_LDTR_SELECTOR);
>  	vmx_dump_dtsel("IDTR:", GUEST_IDTR_LIMIT);
>  	vmx_dump_sel("TR:  ", GUEST_TR_SELECTOR);
> -	if ((vmexit_ctl & (VM_EXIT_SAVE_IA32_PAT | VM_EXIT_SAVE_IA32_EFER)) ||
> -	    (vmentry_ctl & (VM_ENTRY_LOAD_IA32_PAT | VM_ENTRY_LOAD_IA32_EFER)))
> -		pr_err("EFER =     0x%016llx  PAT = 0x%016llx\n",
> -		       vmcs_read64(GUEST_IA32_EFER),
> -		       vmcs_read64(GUEST_IA32_PAT));
> +	if ((vmexit_ctl & VM_EXIT_SAVE_IA32_EFER) ||

Not your code, and completely benign since VM_EXIT_SAVE is never set, but I
don't like checking the VM_EXIT_SAVE_* flag as saving a field on VM-Exit has
zero impact on whether VM-Entry succeeds or fails.  Same complaint on the PAT
field.

> +	    (vmentry_ctl & VM_ENTRY_LOAD_IA32_EFER))
> +		pr_err("EFER= 0x%016llx\n", vmcs_read64(GUEST_IA32_EFER));

Tying into the previous patch, I think we should print both the effective EFER
and vmcs.EFER.  The effective EFER is relevant for several consistency checks.
Maybe something like this?

	pr_err("EFER= 0x%016llx  ", effective_efer);
	if (vmentry_ctl & VM_ENTRY_LOAD_IA32_EFER)
		pr_cont("vmcs.EFER= 0x%016llx\n", vmcs_read64(GUEST_IA32_EFER));
	else
		pr_cont("vmcs.EFER not loaded\n")

> +	if ((vmexit_ctl & VM_EXIT_SAVE_IA32_PAT) ||
> +	    (vmentry_ctl & VM_ENTRY_LOAD_IA32_PAT))
> +		pr_err("PAT = 0x%016llx\n", vmcs_read64(GUEST_IA32_PAT));
>  	pr_err("DebugCtl = 0x%016llx  DebugExceptions = 0x%016lx\n",
>  	       vmcs_read64(GUEST_IA32_DEBUGCTL),
>  	       vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS));
> @@ -5846,10 +5847,10 @@ void dump_vmcs(void)
>  	       vmcs_readl(HOST_IA32_SYSENTER_ESP),
>  	       vmcs_read32(HOST_IA32_SYSENTER_CS),
>  	       vmcs_readl(HOST_IA32_SYSENTER_EIP));
> -	if (vmexit_ctl & (VM_EXIT_LOAD_IA32_PAT | VM_EXIT_LOAD_IA32_EFER))
> -		pr_err("EFER = 0x%016llx  PAT = 0x%016llx\n",
> -		       vmcs_read64(HOST_IA32_EFER),
> -		       vmcs_read64(HOST_IA32_PAT));
> +	if (vmexit_ctl & VM_EXIT_LOAD_IA32_EFER)
> +		pr_err("EFER= 0x%016llx\n", vmcs_read64(HOST_IA32_EFER));
> +	if (vmexit_ctl & VM_EXIT_LOAD_IA32_PAT)
> +		pr_err("PAT = 0x%016llx\n", vmcs_read64(HOST_IA32_PAT));
>  	if (cpu_has_load_perf_global_ctrl() &&
>  	    vmexit_ctl & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
>  		pr_err("PerfGlobCtl = 0x%016llx\n",
> -- 
> 2.30.0
>
David Edmondson Feb. 24, 2021, 1:31 p.m. UTC | #2
On Tuesday, 2021-02-23 at 14:58:29 -08, Sean Christopherson wrote:

> On Fri, Feb 19, 2021, David Edmondson wrote:
>> Show EFER and PAT based on their individual entry/exit controls.
>> 
>> Signed-off-by: David Edmondson <david.edmondson@oracle.com>
>> ---
>>  arch/x86/kvm/vmx/vmx.c | 19 ++++++++++---------
>>  1 file changed, 10 insertions(+), 9 deletions(-)
>> 
>> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
>> index 818051c9fa10..25090e3683ca 100644
>> --- a/arch/x86/kvm/vmx/vmx.c
>> +++ b/arch/x86/kvm/vmx/vmx.c
>> @@ -5805,11 +5805,12 @@ void dump_vmcs(void)
>>  	vmx_dump_sel("LDTR:", GUEST_LDTR_SELECTOR);
>>  	vmx_dump_dtsel("IDTR:", GUEST_IDTR_LIMIT);
>>  	vmx_dump_sel("TR:  ", GUEST_TR_SELECTOR);
>> -	if ((vmexit_ctl & (VM_EXIT_SAVE_IA32_PAT | VM_EXIT_SAVE_IA32_EFER)) ||
>> -	    (vmentry_ctl & (VM_ENTRY_LOAD_IA32_PAT | VM_ENTRY_LOAD_IA32_EFER)))
>> -		pr_err("EFER =     0x%016llx  PAT = 0x%016llx\n",
>> -		       vmcs_read64(GUEST_IA32_EFER),
>> -		       vmcs_read64(GUEST_IA32_PAT));
>> +	if ((vmexit_ctl & VM_EXIT_SAVE_IA32_EFER) ||
>
> Not your code, and completely benign since VM_EXIT_SAVE is never set, but I
> don't like checking the VM_EXIT_SAVE_* flag as saving a field on VM-Exit has
> zero impact on whether VM-Entry succeeds or fails.  Same complaint on the PAT
> field.

Added to v3.

>> +	    (vmentry_ctl & VM_ENTRY_LOAD_IA32_EFER))
>> +		pr_err("EFER= 0x%016llx\n", vmcs_read64(GUEST_IA32_EFER));
>
> Tying into the previous patch, I think we should print both the effective EFER
> and vmcs.EFER.  The effective EFER is relevant for several consistency checks.
> Maybe something like this?
>
> 	pr_err("EFER= 0x%016llx  ", effective_efer);
> 	if (vmentry_ctl & VM_ENTRY_LOAD_IA32_EFER)
> 		pr_cont("vmcs.EFER= 0x%016llx\n", vmcs_read64(GUEST_IA32_EFER));
> 	else
> 		pr_cont("vmcs.EFER not loaded\n")

Added something similar, that makes it clear where the value came from,
in v3.

>> +	if ((vmexit_ctl & VM_EXIT_SAVE_IA32_PAT) ||
>> +	    (vmentry_ctl & VM_ENTRY_LOAD_IA32_PAT))
>> +		pr_err("PAT = 0x%016llx\n", vmcs_read64(GUEST_IA32_PAT));
>>  	pr_err("DebugCtl = 0x%016llx  DebugExceptions = 0x%016lx\n",
>>  	       vmcs_read64(GUEST_IA32_DEBUGCTL),
>>  	       vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS));
>> @@ -5846,10 +5847,10 @@ void dump_vmcs(void)
>>  	       vmcs_readl(HOST_IA32_SYSENTER_ESP),
>>  	       vmcs_read32(HOST_IA32_SYSENTER_CS),
>>  	       vmcs_readl(HOST_IA32_SYSENTER_EIP));
>> -	if (vmexit_ctl & (VM_EXIT_LOAD_IA32_PAT | VM_EXIT_LOAD_IA32_EFER))
>> -		pr_err("EFER = 0x%016llx  PAT = 0x%016llx\n",
>> -		       vmcs_read64(HOST_IA32_EFER),
>> -		       vmcs_read64(HOST_IA32_PAT));
>> +	if (vmexit_ctl & VM_EXIT_LOAD_IA32_EFER)
>> +		pr_err("EFER= 0x%016llx\n", vmcs_read64(HOST_IA32_EFER));
>> +	if (vmexit_ctl & VM_EXIT_LOAD_IA32_PAT)
>> +		pr_err("PAT = 0x%016llx\n", vmcs_read64(HOST_IA32_PAT));
>>  	if (cpu_has_load_perf_global_ctrl() &&
>>  	    vmexit_ctl & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
>>  		pr_err("PerfGlobCtl = 0x%016llx\n",
>> -- 
>> 2.30.0
>> 

dme.
diff mbox series

Patch

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 818051c9fa10..25090e3683ca 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5805,11 +5805,12 @@  void dump_vmcs(void)
 	vmx_dump_sel("LDTR:", GUEST_LDTR_SELECTOR);
 	vmx_dump_dtsel("IDTR:", GUEST_IDTR_LIMIT);
 	vmx_dump_sel("TR:  ", GUEST_TR_SELECTOR);
-	if ((vmexit_ctl & (VM_EXIT_SAVE_IA32_PAT | VM_EXIT_SAVE_IA32_EFER)) ||
-	    (vmentry_ctl & (VM_ENTRY_LOAD_IA32_PAT | VM_ENTRY_LOAD_IA32_EFER)))
-		pr_err("EFER =     0x%016llx  PAT = 0x%016llx\n",
-		       vmcs_read64(GUEST_IA32_EFER),
-		       vmcs_read64(GUEST_IA32_PAT));
+	if ((vmexit_ctl & VM_EXIT_SAVE_IA32_EFER) ||
+	    (vmentry_ctl & VM_ENTRY_LOAD_IA32_EFER))
+		pr_err("EFER= 0x%016llx\n", vmcs_read64(GUEST_IA32_EFER));
+	if ((vmexit_ctl & VM_EXIT_SAVE_IA32_PAT) ||
+	    (vmentry_ctl & VM_ENTRY_LOAD_IA32_PAT))
+		pr_err("PAT = 0x%016llx\n", vmcs_read64(GUEST_IA32_PAT));
 	pr_err("DebugCtl = 0x%016llx  DebugExceptions = 0x%016lx\n",
 	       vmcs_read64(GUEST_IA32_DEBUGCTL),
 	       vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS));
@@ -5846,10 +5847,10 @@  void dump_vmcs(void)
 	       vmcs_readl(HOST_IA32_SYSENTER_ESP),
 	       vmcs_read32(HOST_IA32_SYSENTER_CS),
 	       vmcs_readl(HOST_IA32_SYSENTER_EIP));
-	if (vmexit_ctl & (VM_EXIT_LOAD_IA32_PAT | VM_EXIT_LOAD_IA32_EFER))
-		pr_err("EFER = 0x%016llx  PAT = 0x%016llx\n",
-		       vmcs_read64(HOST_IA32_EFER),
-		       vmcs_read64(HOST_IA32_PAT));
+	if (vmexit_ctl & VM_EXIT_LOAD_IA32_EFER)
+		pr_err("EFER= 0x%016llx\n", vmcs_read64(HOST_IA32_EFER));
+	if (vmexit_ctl & VM_EXIT_LOAD_IA32_PAT)
+		pr_err("PAT = 0x%016llx\n", vmcs_read64(HOST_IA32_PAT));
 	if (cpu_has_load_perf_global_ctrl() &&
 	    vmexit_ctl & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
 		pr_err("PerfGlobCtl = 0x%016llx\n",