Commit 2f2bc6af authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: selftests: Add vcpu_arch_put_guest() to do writes from guest code 

Introduce a macro, vcpu_arch_put_guest(), for "putting" values to memory
from guest code in "interesting" situations, e.g. when writing memory that
is being dirty logged.  Structure the macro so that arch code can provide
a custom implementation, e.g. x86 will use the macro to force emulation of
the access.

Use the helper in dirty_log_test, which is of particular interest (see
above), and in xen_shinfo_test, which isn't all that interesting, but
provides a second usage of the macro with a different size operand
(uint8_t versus uint64_t), i.e. to help verify that the macro works for
more than just 64-bit values.

Use "put" as the verb to align with the kernel's {get,put}_user()
terminology.

Link: https://lore.kernel.org/r/20240314185459.2439072-5-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent e1ff1152

tools/testing/selftests/kvm/dirty_log_test.c

+3 −2
Original line number Diff line number Diff line
@@ -105,7 +105,7 @@ static void guest_code(void) 
	 */

	for (i = 0; i < guest_num_pages; i++) {

		addr = guest_test_virt_mem + i * guest_page_size;

		*(uint64_t *)addr = READ_ONCE(iteration);

		vcpu_arch_put_guest(*(uint64_t *)addr, READ_ONCE(iteration));

	}



	while (true) {
@@ -114,7 +114,8 @@ static void guest_code(void) 
			addr += (guest_random_u64(&guest_rng) % guest_num_pages)

				* guest_page_size;

			addr = align_down(addr, host_page_size);

			*(uint64_t *)addr = READ_ONCE(iteration);



			vcpu_arch_put_guest(*(uint64_t *)addr, READ_ONCE(iteration));

		}



		GUEST_SYNC(1);

tools/testing/selftests/kvm/include/kvm_util_base.h

+3 −0
Original line number Diff line number Diff line
@@ -609,6 +609,9 @@ void *addr_gva2hva(struct kvm_vm *vm, vm_vaddr_t gva); 
vm_paddr_t addr_hva2gpa(struct kvm_vm *vm, void *hva);

void *addr_gpa2alias(struct kvm_vm *vm, vm_paddr_t gpa);



#ifndef vcpu_arch_put_guest

#define vcpu_arch_put_guest(mem, val) do { (mem) = (val); } while (0)

#endif



static inline vm_paddr_t vm_untag_gpa(struct kvm_vm *vm, vm_paddr_t gpa)

{

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

+3 −2
Original line number Diff line number Diff line
@@ -171,8 +171,9 @@ static volatile bool guest_saw_irq; 
static void evtchn_handler(struct ex_regs *regs)

{

	struct vcpu_info *vi = (void *)VCPU_INFO_VADDR;

	vi->evtchn_upcall_pending = 0;

	vi->evtchn_pending_sel = 0;



	vcpu_arch_put_guest(vi->evtchn_upcall_pending, 0);

	vcpu_arch_put_guest(vi->evtchn_pending_sel, 0);

	guest_saw_irq = true;



	GUEST_SYNC(TEST_GUEST_SAW_IRQ);