Commit c0c76d99 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: selftests: Add helpers to make Xen-style VMCALL/VMMCALL hypercalls 



Add wrappers to do hypercalls using VMCALL/VMMCALL and Xen's register ABI
(as opposed to full Xen-style hypercalls through a hypervisor provided
page).  Using the common helpers dedups a pile of code, and uses the
native hypercall instruction when running on AMD.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20230204024151.1373296-3-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 4009e0bb

tools/testing/selftests/kvm/include/x86_64/processor.h

+2 −0
Original line number Diff line number Diff line
@@ -1063,6 +1063,8 @@ uint64_t *vm_get_page_table_entry(struct kvm_vm *vm, uint64_t vaddr); 


uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2,

		       uint64_t a3);

uint64_t __xen_hypercall(uint64_t nr, uint64_t a0, void *a1);

void xen_hypercall(uint64_t nr, uint64_t a0, void *a1);



void __vm_xsave_require_permission(int bit, const char *name);

tools/testing/selftests/kvm/lib/x86_64/processor.c

+10 −0
Original line number Diff line number Diff line
@@ -1161,6 +1161,16 @@ uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2, 
	return X86_HYPERCALL("a"(nr), "b"(a0), "c"(a1), "d"(a2), "S"(a3));

}



uint64_t __xen_hypercall(uint64_t nr, uint64_t a0, void *a1)

{

	return X86_HYPERCALL("a"(nr), "D"(a0), "S"(a1));

}



void xen_hypercall(uint64_t nr, uint64_t a0, void *a1)

{

	GUEST_ASSERT(!__xen_hypercall(nr, a0, a1));

}



const struct kvm_cpuid2 *kvm_get_supported_hv_cpuid(void)

{

	static struct kvm_cpuid2 *cpuid;

tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c

+9 −54
Original line number Diff line number Diff line
@@ -225,15 +225,8 @@ static void guest_code(void) 


	/* Our turn. Deliver event channel (to ourselves) with

	 * 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));



	GUEST_ASSERT(rax == 0);

	xen_hypercall(__HYPERVISOR_event_channel_op, EVTCHNOP_send, &s);



	guest_wait_for_irq();
@@ -242,24 +235,15 @@ 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));



	GUEST_ASSERT(rax == 0);

	xen_hypercall(__HYPERVISOR_event_channel_op, EVTCHNOP_send, &s);



	guest_wait_for_irq();



	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));

	GUEST_ASSERT(rax == 0);

	xen_hypercall(__HYPERVISOR_set_timer_op,

		      rs->state_entry_time + 100000000, NULL);



	GUEST_SYNC(14);
@@ -281,37 +265,19 @@ static void guest_code(void) 
		.timeout = 0,

	};



	__asm__ __volatile__ ("vmcall" :

			      "=a" (rax) :

			      "a" (__HYPERVISOR_sched_op),

			      "D" (SCHEDOP_poll),

			      "S" (&p));



	GUEST_ASSERT(rax == 0);

	xen_hypercall(__HYPERVISOR_sched_op, SCHEDOP_poll, &p);



	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));



	GUEST_ASSERT(rax == 0);

	xen_hypercall(__HYPERVISOR_sched_op, SCHEDOP_poll, &p);



	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));



	GUEST_ASSERT(rax == 0);

	xen_hypercall(__HYPERVISOR_sched_op, SCHEDOP_poll, &p);



	GUEST_SYNC(19);
@@ -319,13 +285,7 @@ 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));



	GUEST_ASSERT(rax == 0);

	xen_hypercall(__HYPERVISOR_sched_op, SCHEDOP_poll, &p);



	guest_wait_for_irq();
@@ -360,12 +320,7 @@ static void guest_code(void) 
	 * timer IRQ is dropped due to an invalid event channel.

	 */

	for (i = 0; i < 100 && !guest_saw_irq; i++)

		asm volatile("vmcall"

			     : "=a" (rax)

			     : "a" (__HYPERVISOR_sched_op),

			       "D" (SCHEDOP_poll),

			       "S" (&p)

			     : "memory");

		__xen_hypercall(__HYPERVISOR_sched_op, SCHEDOP_poll, &p);



	/*

	 * Re-send the timer IRQ if it was (likely) dropped due to the timer