Commit 0303ffdb authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: selftests: arm64: Check for supported page sizes 



Just as arm64 implemenations don't necessary support all IPA
ranges, they don't  all support the same page sizes either. Fun.

Create a dummy VM to snapshot the page sizes supported by the
host, and filter the supported modes.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarAndrew Jones <drjones@redhat.com>
Link: https://lore.kernel.org/r/20211227124809.1335409-4-maz@kernel.org
parent 357c628e

tools/testing/selftests/kvm/include/aarch64/processor.h

+3 −0
Original line number Diff line number Diff line
@@ -113,6 +113,9 @@ enum { 
#define ESR_EC_WP_CURRENT	0x35

#define ESR_EC_BRK_INS		0x3c



void aarch64_get_supported_page_sizes(uint32_t ipa,

				      bool *ps4k, bool *ps16k, bool *ps64k);



void vm_init_descriptor_tables(struct kvm_vm *vm);

void vcpu_init_descriptor_tables(struct kvm_vm *vm, uint32_t vcpuid);

tools/testing/selftests/kvm/lib/aarch64/processor.c

+36 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/compiler.h>

#include <assert.h>



#include "guest_modes.h"

#include "kvm_util.h"

#include "../kvm_util_internal.h"

#include "processor.h"
@@ -433,6 +434,41 @@ uint32_t guest_get_vcpuid(void) 
	return read_sysreg(tpidr_el1);

}



void aarch64_get_supported_page_sizes(uint32_t ipa,

				      bool *ps4k, bool *ps16k, bool *ps64k)

{

	struct kvm_vcpu_init preferred_init;

	int kvm_fd, vm_fd, vcpu_fd, err;

	uint64_t val;

	struct kvm_one_reg reg = {

		.id	= KVM_ARM64_SYS_REG(SYS_ID_AA64MMFR0_EL1),

		.addr	= (uint64_t)&val,

	};



	kvm_fd = open_kvm_dev_path_or_exit();

	vm_fd = ioctl(kvm_fd, KVM_CREATE_VM, ipa);

	TEST_ASSERT(vm_fd >= 0, "Can't create VM");



	vcpu_fd = ioctl(vm_fd, KVM_CREATE_VCPU, 0);

	TEST_ASSERT(vcpu_fd >= 0, "Can't create vcpu");



	err = ioctl(vm_fd, KVM_ARM_PREFERRED_TARGET, &preferred_init);

	TEST_ASSERT(err == 0, "Can't get target");

	err = ioctl(vcpu_fd, KVM_ARM_VCPU_INIT, &preferred_init);

	TEST_ASSERT(err == 0, "Can't get init vcpu");



	err = ioctl(vcpu_fd, KVM_GET_ONE_REG, &reg);

	TEST_ASSERT(err == 0, "Can't get MMFR0");



	*ps4k = ((val >> 28) & 0xf) != 0xf;

	*ps64k = ((val >> 24) & 0xf) == 0;

	*ps16k = ((val >> 20) & 0xf) != 0;



	close(vcpu_fd);

	close(vm_fd);

	close(kvm_fd);

}



/*

 * arm64 doesn't have a true default mode, so start by computing the

 * available IPA space and page sizes early.

tools/testing/selftests/kvm/lib/guest_modes.c

+11 −6
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include "guest_modes.h"



#ifdef __aarch64__

#include "processor.h"

enum vm_guest_mode vm_mode_default;

#endif
@@ -17,19 +18,23 @@ void guest_modes_append_default(void) 
#else

	{

		unsigned int limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE);

		bool ps4k, ps16k, ps64k;

		int i;



		aarch64_get_supported_page_sizes(limit, &ps4k, &ps16k, &ps64k);



		vm_mode_default = NUM_VM_MODES;



		if (limit >= 52)

			guest_mode_append(VM_MODE_P52V48_64K, true, true);

			guest_mode_append(VM_MODE_P52V48_64K, ps64k, ps64k);

		if (limit >= 48) {

			guest_mode_append(VM_MODE_P48V48_4K, true, true);

			guest_mode_append(VM_MODE_P48V48_64K, true, true);

			guest_mode_append(VM_MODE_P48V48_4K, ps4k, ps4k);

			guest_mode_append(VM_MODE_P48V48_64K, ps64k, ps64k);

		}

		if (limit >= 40) {

			guest_mode_append(VM_MODE_P40V48_4K, true, true);

			guest_mode_append(VM_MODE_P40V48_64K, true, true);

			guest_mode_append(VM_MODE_P40V48_4K, ps4k, ps4k);

			guest_mode_append(VM_MODE_P40V48_64K, ps64k, ps64k);

			if (ps4k)

				vm_mode_default = VM_MODE_P40V48_4K;

		}