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[V2 PATCH 8/8] KVM: selftests: x86: xen: Execute cpu specific vmcall instruction

Vishal Annapurve posted 8 patches 3 years, 6 months ago
[V2 PATCH 8/8] KVM: selftests: x86: xen: Execute cpu specific vmcall instruction
Posted by Vishal Annapurve 3 years, 6 months ago 
Update xen specific hypercall invocation to execute cpu specific vmcall
instructions.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Vishal Annapurve <vannapurve@google.com>
---
 .../selftests/kvm/x86_64/xen_shinfo_test.c    | 64 +++++++------------
 .../selftests/kvm/x86_64/xen_vmcall_test.c    | 14 ++--
 2 files changed, 34 insertions(+), 44 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
index 8a5cb800f50e..92ed07f1c772 100644
--- a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
+++ b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
@@ -145,6 +145,23 @@ static void guest_wait_for_irq(void)
 	guest_saw_irq = false;
 }
 
+static unsigned long vmcall_helper(unsigned long reg_a, unsigned long reg_di,
+	unsigned long reg_si)
+{
+	unsigned long ret;
+
+	if (is_amd_cpu())
+		__asm__ __volatile__ ("vmmcall" :
+			"=a" (ret) :
+			"a" (reg_a), "D" (reg_di), "S" (reg_si));
+	else
+		__asm__ __volatile__ ("vmcall" :
+			"=a" (ret) :
+			"a" (reg_a), "D" (reg_di), "S" (reg_si));
+
+	return ret;
+}
+
 static void guest_code(void)
 {
 	struct vcpu_runstate_info *rs = (void *)RUNSTATE_VADDR;
@@ -217,12 +234,7 @@ static void guest_code(void)
 	 * EVTCHNOP_send hypercall. */
 	unsigned long rax;
 	struct evtchn_send s = { .port = 127 };
-	__asm__ __volatile__ ("vmcall" :
-			      "=a" (rax) :
-			      "a" (__HYPERVISOR_event_channel_op),
-			      "D" (EVTCHNOP_send),
-			      "S" (&s));
-
+	rax = vmcall_helper(__HYPERVISOR_event_channel_op, EVTCHNOP_send, (unsigned long)&s);
 	GUEST_ASSERT(rax == 0);
 
 	guest_wait_for_irq();
@@ -232,12 +244,7 @@ static void guest_code(void)
 	/* Deliver "outbound" event channel to an eventfd which
 	 * happens to be one of our own irqfds. */
 	s.port = 197;
-	__asm__ __volatile__ ("vmcall" :
-			      "=a" (rax) :
-			      "a" (__HYPERVISOR_event_channel_op),
-			      "D" (EVTCHNOP_send),
-			      "S" (&s));
-
+	rax = vmcall_helper(__HYPERVISOR_event_channel_op, EVTCHNOP_send, (unsigned long)&s);
 	GUEST_ASSERT(rax == 0);
 
 	guest_wait_for_irq();
@@ -245,10 +252,7 @@ static void guest_code(void)
 	GUEST_SYNC(13);
 
 	/* Set a timer 100ms in the future. */
-	__asm__ __volatile__ ("vmcall" :
-			      "=a" (rax) :
-			      "a" (__HYPERVISOR_set_timer_op),
-			      "D" (rs->state_entry_time + 100000000));
+	rax = vmcall_helper(__HYPERVISOR_set_timer_op, (rs->state_entry_time + 100000000), 0);
 	GUEST_ASSERT(rax == 0);
 
 	GUEST_SYNC(14);
@@ -271,36 +275,21 @@ static void guest_code(void)
 		.timeout = 0,
 	};
 
-	__asm__ __volatile__ ("vmcall" :
-			      "=a" (rax) :
-			      "a" (__HYPERVISOR_sched_op),
-			      "D" (SCHEDOP_poll),
-			      "S" (&p));
-
+	rax = vmcall_helper(__HYPERVISOR_sched_op, SCHEDOP_poll, (unsigned long)&p);
 	GUEST_ASSERT(rax == 0);
 
 	GUEST_SYNC(17);
 
 	/* Poll for an unset port and wait for the timeout. */
 	p.timeout = 100000000;
-	__asm__ __volatile__ ("vmcall" :
-			      "=a" (rax) :
-			      "a" (__HYPERVISOR_sched_op),
-			      "D" (SCHEDOP_poll),
-			      "S" (&p));
-
+	rax = vmcall_helper(__HYPERVISOR_sched_op, SCHEDOP_poll, (unsigned long)&p);
 	GUEST_ASSERT(rax == 0);
 
 	GUEST_SYNC(18);
 
 	/* A timer will wake the masked port we're waiting on, while we poll */
 	p.timeout = 0;
-	__asm__ __volatile__ ("vmcall" :
-			      "=a" (rax) :
-			      "a" (__HYPERVISOR_sched_op),
-			      "D" (SCHEDOP_poll),
-			      "S" (&p));
-
+	rax = vmcall_helper(__HYPERVISOR_sched_op, SCHEDOP_poll, (unsigned long)&p);
 	GUEST_ASSERT(rax == 0);
 
 	GUEST_SYNC(19);
@@ -309,12 +298,7 @@ static void guest_code(void)
 	 * actual interrupt, while we're polling on a different port. */
 	ports[0]++;
 	p.timeout = 0;
-	__asm__ __volatile__ ("vmcall" :
-			      "=a" (rax) :
-			      "a" (__HYPERVISOR_sched_op),
-			      "D" (SCHEDOP_poll),
-			      "S" (&p));
-
+	rax = vmcall_helper(__HYPERVISOR_sched_op, SCHEDOP_poll, (unsigned long)&p);
 	GUEST_ASSERT(rax == 0);
 
 	guest_wait_for_irq();
diff --git a/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c b/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
index 88914d48c65e..e78f1b5d3af8 100644
--- a/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
+++ b/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
@@ -37,10 +37,16 @@ static void guest_code(void)
 	register unsigned long r9 __asm__("r9") = ARGVALUE(6);
 
 	/* First a direct invocation of 'vmcall' */
-	__asm__ __volatile__("vmcall" :
-			     "=a"(rax) :
-			     "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
-			     "r"(r10), "r"(r8), "r"(r9));
+	if (is_amd_cpu())
+		__asm__ __volatile__("vmmcall" :
+			"=a"(rax) :
+			"a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
+			"r"(r10), "r"(r8), "r"(r9));
+	else
+		__asm__ __volatile__("vmcall" :
+			"=a"(rax) :
+			"a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
+			"r"(r10), "r"(r8), "r"(r9));
 	GUEST_ASSERT(rax == RETVALUE);
 
 	/* Fill in the Xen hypercall page */
-- 
2.37.2.789.g6183377224-goog
Re: [V2 PATCH 8/8] KVM: selftests: x86: xen: Execute cpu specific vmcall instruction
Posted by David Matlack 3 years, 6 months ago 
On Thu, Sep 15, 2022 at 12:04:48AM +0000, Vishal Annapurve wrote:
> Update xen specific hypercall invocation to execute cpu specific vmcall
> instructions.
> 
> Suggested-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Vishal Annapurve <vannapurve@google.com>
> ---
>  .../selftests/kvm/x86_64/xen_shinfo_test.c    | 64 +++++++------------
>  .../selftests/kvm/x86_64/xen_vmcall_test.c    | 14 ++--
>  2 files changed, 34 insertions(+), 44 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
> index 8a5cb800f50e..92ed07f1c772 100644
> --- a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
> @@ -145,6 +145,23 @@ static void guest_wait_for_irq(void)
>  	guest_saw_irq = false;
>  }
>  
> +static unsigned long vmcall_helper(unsigned long reg_a, unsigned long reg_di,
> +	unsigned long reg_si)
> +{
> +	unsigned long ret;
> +
> +	if (is_amd_cpu())
> +		__asm__ __volatile__ ("vmmcall" :
> +			"=a" (ret) :
> +			"a" (reg_a), "D" (reg_di), "S" (reg_si));
> +	else
> +		__asm__ __volatile__ ("vmcall" :
> +			"=a" (ret) :
> +			"a" (reg_a), "D" (reg_di), "S" (reg_si));
> +
> +	return ret;
> +}
> +
>  static void guest_code(void)
>  {
>  	struct vcpu_runstate_info *rs = (void *)RUNSTATE_VADDR;
> @@ -217,12 +234,7 @@ static void guest_code(void)
>  	 * EVTCHNOP_send hypercall. */
>  	unsigned long rax;
>  	struct evtchn_send s = { .port = 127 };
> -	__asm__ __volatile__ ("vmcall" :
> -			      "=a" (rax) :
> -			      "a" (__HYPERVISOR_event_channel_op),
> -			      "D" (EVTCHNOP_send),
> -			      "S" (&s));
> -
> +	rax = vmcall_helper(__HYPERVISOR_event_channel_op, EVTCHNOP_send, (unsigned long)&s);
>  	GUEST_ASSERT(rax == 0);
>  
>  	guest_wait_for_irq();
> @@ -232,12 +244,7 @@ static void guest_code(void)
>  	/* Deliver "outbound" event channel to an eventfd which
>  	 * happens to be one of our own irqfds. */
>  	s.port = 197;
> -	__asm__ __volatile__ ("vmcall" :
> -			      "=a" (rax) :
> -			      "a" (__HYPERVISOR_event_channel_op),
> -			      "D" (EVTCHNOP_send),
> -			      "S" (&s));
> -
> +	rax = vmcall_helper(__HYPERVISOR_event_channel_op, EVTCHNOP_send, (unsigned long)&s);
>  	GUEST_ASSERT(rax == 0);
>  
>  	guest_wait_for_irq();
> @@ -245,10 +252,7 @@ static void guest_code(void)
>  	GUEST_SYNC(13);
>  
>  	/* Set a timer 100ms in the future. */
> -	__asm__ __volatile__ ("vmcall" :
> -			      "=a" (rax) :
> -			      "a" (__HYPERVISOR_set_timer_op),
> -			      "D" (rs->state_entry_time + 100000000));
> +	rax = vmcall_helper(__HYPERVISOR_set_timer_op, (rs->state_entry_time + 100000000), 0);
>  	GUEST_ASSERT(rax == 0);
>  
>  	GUEST_SYNC(14);
> @@ -271,36 +275,21 @@ static void guest_code(void)
>  		.timeout = 0,
>  	};
>  
> -	__asm__ __volatile__ ("vmcall" :
> -			      "=a" (rax) :
> -			      "a" (__HYPERVISOR_sched_op),
> -			      "D" (SCHEDOP_poll),
> -			      "S" (&p));
> -
> +	rax = vmcall_helper(__HYPERVISOR_sched_op, SCHEDOP_poll, (unsigned long)&p);
>  	GUEST_ASSERT(rax == 0);
>  
>  	GUEST_SYNC(17);
>  
>  	/* Poll for an unset port and wait for the timeout. */
>  	p.timeout = 100000000;
> -	__asm__ __volatile__ ("vmcall" :
> -			      "=a" (rax) :
> -			      "a" (__HYPERVISOR_sched_op),
> -			      "D" (SCHEDOP_poll),
> -			      "S" (&p));
> -
> +	rax = vmcall_helper(__HYPERVISOR_sched_op, SCHEDOP_poll, (unsigned long)&p);
>  	GUEST_ASSERT(rax == 0);
>  
>  	GUEST_SYNC(18);
>  
>  	/* A timer will wake the masked port we're waiting on, while we poll */
>  	p.timeout = 0;
> -	__asm__ __volatile__ ("vmcall" :
> -			      "=a" (rax) :
> -			      "a" (__HYPERVISOR_sched_op),
> -			      "D" (SCHEDOP_poll),
> -			      "S" (&p));
> -
> +	rax = vmcall_helper(__HYPERVISOR_sched_op, SCHEDOP_poll, (unsigned long)&p);
>  	GUEST_ASSERT(rax == 0);
>  
>  	GUEST_SYNC(19);
> @@ -309,12 +298,7 @@ static void guest_code(void)
>  	 * actual interrupt, while we're polling on a different port. */
>  	ports[0]++;
>  	p.timeout = 0;
> -	__asm__ __volatile__ ("vmcall" :
> -			      "=a" (rax) :
> -			      "a" (__HYPERVISOR_sched_op),
> -			      "D" (SCHEDOP_poll),
> -			      "S" (&p));
> -
> +	rax = vmcall_helper(__HYPERVISOR_sched_op, SCHEDOP_poll, (unsigned long)&p);
>  	GUEST_ASSERT(rax == 0);
>  
>  	guest_wait_for_irq();
> diff --git a/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c b/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
> index 88914d48c65e..e78f1b5d3af8 100644
> --- a/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
> @@ -37,10 +37,16 @@ static void guest_code(void)
>  	register unsigned long r9 __asm__("r9") = ARGVALUE(6);
>  
>  	/* First a direct invocation of 'vmcall' */
> -	__asm__ __volatile__("vmcall" :
> -			     "=a"(rax) :
> -			     "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
> -			     "r"(r10), "r"(r8), "r"(r9));
> +	if (is_amd_cpu())
> +		__asm__ __volatile__("vmmcall" :
> +			"=a"(rax) :
> +			"a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
> +			"r"(r10), "r"(r8), "r"(r9));
> +	else
> +		__asm__ __volatile__("vmcall" :
> +			"=a"(rax) :
> +			"a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
> +			"r"(r10), "r"(r8), "r"(r9));

Can we create common helper functions or macros for doing hypercalls to
reduce the amount of duplicated inline assembly?

>  	GUEST_ASSERT(rax == RETVALUE);
>  
>  	/* Fill in the Xen hypercall page */
> -- 
> 2.37.2.789.g6183377224-goog
>
Re: [V2 PATCH 8/8] KVM: selftests: x86: xen: Execute cpu specific vmcall instruction
Posted by Vishal Annapurve 3 years, 6 months ago 
On Wed, Sep 21, 2022 at 2:47 PM David Matlack <dmatlack@google.com> wrote:
>
> On Thu, Sep 15, 2022 at 12:04:48AM +0000, Vishal Annapurve wrote:
> > Update xen specific hypercall invocation to execute cpu specific vmcall
> > instructions.
> >
> > Suggested-by: Sean Christopherson <seanjc@google.com>
> > Signed-off-by: Vishal Annapurve <vannapurve@google.com>
> > ---
> >  .../selftests/kvm/x86_64/xen_shinfo_test.c    | 64 +++++++------------
> >  .../selftests/kvm/x86_64/xen_vmcall_test.c    | 14 ++--
> >  2 files changed, 34 insertions(+), 44 deletions(-)
> > ...
> > diff --git a/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c b/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
> > index 88914d48c65e..e78f1b5d3af8 100644
> > --- a/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
> > +++ b/tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c
> > @@ -37,10 +37,16 @@ static void guest_code(void)
> >       register unsigned long r9 __asm__("r9") = ARGVALUE(6);
> >
> >       /* First a direct invocation of 'vmcall' */
> > -     __asm__ __volatile__("vmcall" :
> > -                          "=a"(rax) :
> > -                          "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
> > -                          "r"(r10), "r"(r8), "r"(r9));
> > +     if (is_amd_cpu())
> > +             __asm__ __volatile__("vmmcall" :
> > +                     "=a"(rax) :
> > +                     "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
> > +                     "r"(r10), "r"(r8), "r"(r9));
> > +     else
> > +             __asm__ __volatile__("vmcall" :
> > +                     "=a"(rax) :
> > +                     "a"(rax), "D"(rdi), "S"(rsi), "d"(rdx),
> > +                     "r"(r10), "r"(r8), "r"(r9));
>
> Can we create common helper functions or macros for doing hypercalls to
> reduce the amount of duplicated inline assembly?
>

Ack, will fix this in the next series.

> >       GUEST_ASSERT(rax == RETVALUE);
> >
> >       /* Fill in the Xen hypercall page */
> > --
> > 2.37.2.789.g6183377224-goog
> >

Patchew 2.1-devel-ea86937

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