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* [kvm-unit-tests PATCH v2] x86: VMX: Check precondition for RDTSC test
@ 2020-01-22 10:03 Oliver Upton
  2020-01-22 11:39 ` Vitaly Kuznetsov
  2020-01-22 14:40 ` Paolo Bonzini
  0 siblings, 2 replies; 3+ messages in thread
From: Oliver Upton @ 2020-01-22 10:03 UTC (permalink / raw)
  To: kvm; +Cc: Paolo Bonzini, Jim Mattson, Oliver Upton, Aaron Lewis,
	Vitaly Kuznetsov

The RDTSC VM-exit test requires the 'use TSC offsetting' processor-based
VM-execution control be allowed on the host. Check this precondition
before running the test rather than asserting it later on to avoid
erroneous failures on a host without TSC offsetting.

Cc: Aaron Lewis <aaronlewis@google.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Oliver Upton <oupton@google.com>
---
 x86/vmx_tests.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
index 3b150323b325..b31c360c5f3c 100644
--- a/x86/vmx_tests.c
+++ b/x86/vmx_tests.c
@@ -9161,9 +9161,6 @@ static void vmx_vmcs_shadow_test(void)
  */
 static void reset_guest_tsc_to_zero(void)
 {
-	TEST_ASSERT_MSG(ctrl_cpu_rev[0].clr & CPU_USE_TSC_OFFSET,
-			"Expected support for 'use TSC offsetting'");
-
 	vmcs_set_bits(CPU_EXEC_CTRL0, CPU_USE_TSC_OFFSET);
 	vmcs_write(TSC_OFFSET, -rdtsc());
 }
@@ -9210,6 +9207,9 @@ static void rdtsc_vmexit_diff_test(void)
 	int fail = 0;
 	int i;
 
+	if (!(ctrl_cpu_rev[0].clr & CPU_USE_TSC_OFFSET))
+		test_skip("CPU doesn't support the 'use TSC offsetting' processor-based VM-execution control.\n");
+
 	test_set_guest(rdtsc_vmexit_diff_test_guest);
 
 	reset_guest_tsc_to_zero();
-- 
2.25.0.341.g760bfbb309-goog


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [kvm-unit-tests PATCH v2] x86: VMX: Check precondition for RDTSC test
  2020-01-22 10:03 [kvm-unit-tests PATCH v2] x86: VMX: Check precondition for RDTSC test Oliver Upton
@ 2020-01-22 11:39 ` Vitaly Kuznetsov
  2020-01-22 14:40 ` Paolo Bonzini
  1 sibling, 0 replies; 3+ messages in thread
From: Vitaly Kuznetsov @ 2020-01-22 11:39 UTC (permalink / raw)
  To: Oliver Upton, kvm; +Cc: Paolo Bonzini, Jim Mattson, Oliver Upton, Aaron Lewis

Oliver Upton <oupton@google.com> writes:

> The RDTSC VM-exit test requires the 'use TSC offsetting' processor-based
> VM-execution control be allowed on the host. Check this precondition
> before running the test rather than asserting it later on to avoid
> erroneous failures on a host without TSC offsetting.
>
> Cc: Aaron Lewis <aaronlewis@google.com>
> Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
> Signed-off-by: Oliver Upton <oupton@google.com>
> ---
>  x86/vmx_tests.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
> index 3b150323b325..b31c360c5f3c 100644
> --- a/x86/vmx_tests.c
> +++ b/x86/vmx_tests.c
> @@ -9161,9 +9161,6 @@ static void vmx_vmcs_shadow_test(void)
>   */
>  static void reset_guest_tsc_to_zero(void)
>  {
> -	TEST_ASSERT_MSG(ctrl_cpu_rev[0].clr & CPU_USE_TSC_OFFSET,
> -			"Expected support for 'use TSC offsetting'");
> -
>  	vmcs_set_bits(CPU_EXEC_CTRL0, CPU_USE_TSC_OFFSET);
>  	vmcs_write(TSC_OFFSET, -rdtsc());
>  }
> @@ -9210,6 +9207,9 @@ static void rdtsc_vmexit_diff_test(void)
>  	int fail = 0;
>  	int i;
>  
> +	if (!(ctrl_cpu_rev[0].clr & CPU_USE_TSC_OFFSET))
> +		test_skip("CPU doesn't support the 'use TSC offsetting' processor-based VM-execution control.\n");
> +
>  	test_set_guest(rdtsc_vmexit_diff_test_guest);
>  
>  	reset_guest_tsc_to_zero();

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>

-- 
Vitaly


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [kvm-unit-tests PATCH v2] x86: VMX: Check precondition for RDTSC test
  2020-01-22 10:03 [kvm-unit-tests PATCH v2] x86: VMX: Check precondition for RDTSC test Oliver Upton
  2020-01-22 11:39 ` Vitaly Kuznetsov
@ 2020-01-22 14:40 ` Paolo Bonzini
  1 sibling, 0 replies; 3+ messages in thread
From: Paolo Bonzini @ 2020-01-22 14:40 UTC (permalink / raw)
  To: Oliver Upton, kvm; +Cc: Jim Mattson, Aaron Lewis, Vitaly Kuznetsov

On 22/01/20 11:03, Oliver Upton wrote:
> The RDTSC VM-exit test requires the 'use TSC offsetting' processor-based
> VM-execution control be allowed on the host. Check this precondition
> before running the test rather than asserting it later on to avoid
> erroneous failures on a host without TSC offsetting.
> 
> Cc: Aaron Lewis <aaronlewis@google.com>
> Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
> Signed-off-by: Oliver Upton <oupton@google.com>
> ---
>  x86/vmx_tests.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
> index 3b150323b325..b31c360c5f3c 100644
> --- a/x86/vmx_tests.c
> +++ b/x86/vmx_tests.c
> @@ -9161,9 +9161,6 @@ static void vmx_vmcs_shadow_test(void)
>   */
>  static void reset_guest_tsc_to_zero(void)
>  {
> -	TEST_ASSERT_MSG(ctrl_cpu_rev[0].clr & CPU_USE_TSC_OFFSET,
> -			"Expected support for 'use TSC offsetting'");
> -
>  	vmcs_set_bits(CPU_EXEC_CTRL0, CPU_USE_TSC_OFFSET);
>  	vmcs_write(TSC_OFFSET, -rdtsc());
>  }
> @@ -9210,6 +9207,9 @@ static void rdtsc_vmexit_diff_test(void)
>  	int fail = 0;
>  	int i;
>  
> +	if (!(ctrl_cpu_rev[0].clr & CPU_USE_TSC_OFFSET))
> +		test_skip("CPU doesn't support the 'use TSC offsetting' processor-based VM-execution control.\n");
> +
>  	test_set_guest(rdtsc_vmexit_diff_test_guest);
>  
>  	reset_guest_tsc_to_zero();
> 

Queued this one now, thanks.

Paolo


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2020-01-22 14:40 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2020-01-22 10:03 [kvm-unit-tests PATCH v2] x86: VMX: Check precondition for RDTSC test Oliver Upton
2020-01-22 11:39 ` Vitaly Kuznetsov
2020-01-22 14:40 ` Paolo Bonzini

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