[PATCH v2] KVM: riscv: selftests: Add riscv vm satp modes
Wu Fei
atwufei at 163.com
Tue Nov 4 04:53:27 PST 2025
On 11/4/25 15:41, Anup Patel wrote:
> On Wed, Oct 29, 2025 at 5:09 PM <wu.fei9 at sanechips.com.cn> wrote:
>>
>> Current vm modes cannot represent riscv guest modes precisely, here add
>> all 9 combinations of P(56,40,41) x V(57,48,39). Also the default vm
>> mode is detected on runtime instead of hardcoded one, which might not be
>> supported on specific machine.
>>
>> Signed-off-by: Wu Fei <wu.fei9 at sanechips.com.cn>
>
> LGTM.
>
> Reviewed-by: Anup Patel <anup at brainfault.org>
>
> Please resend the patch CC'ing kvm at vger.kernel.org so that
> folks working other architectures can also review.
OK. As my company account is not working with git-send-email yet, is it
a valid option to use my personal email to send the patch on behalf of
company account?
Thanks,
Fei.
>
> Regards,
> Anup
>
>> ---
>> .../testing/selftests/kvm/include/kvm_util.h | 17 ++++-
>> .../selftests/kvm/include/riscv/processor.h | 2 +
>> tools/testing/selftests/kvm/lib/guest_modes.c | 41 +++++++++---
>> tools/testing/selftests/kvm/lib/kvm_util.c | 33 ++++++++++
>> .../selftests/kvm/lib/riscv/processor.c | 63 +++++++++++++++++--
>> 5 files changed, 142 insertions(+), 14 deletions(-)
>>
>> diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
>> index bee65ca08721..2055f0f5df82 100644
>> --- a/tools/testing/selftests/kvm/include/kvm_util.h
>> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
>> @@ -179,6 +179,17 @@ enum vm_guest_mode {
>> VM_MODE_P36V48_64K,
>> VM_MODE_P47V47_16K,
>> VM_MODE_P36V47_16K,
>> +
>> + VM_MODE_P56V57_4K, /* For riscv64 */
>> + VM_MODE_P56V48_4K,
>> + VM_MODE_P56V39_4K,
>> + VM_MODE_P50V57_4K,
>> + VM_MODE_P50V48_4K,
>> + VM_MODE_P50V39_4K,
>> + VM_MODE_P41V57_4K,
>> + VM_MODE_P41V48_4K,
>> + VM_MODE_P41V39_4K,
>> +
>> NUM_VM_MODES,
>> };
>>
>> @@ -203,10 +214,10 @@ kvm_static_assert(sizeof(struct vm_shape) == sizeof(uint64_t));
>> shape; \
>> })
>>
>> -#if defined(__aarch64__)
>> -
>> extern enum vm_guest_mode vm_mode_default;
>>
>> +#if defined(__aarch64__)
>> +
>> #define VM_MODE_DEFAULT vm_mode_default
>> #define MIN_PAGE_SHIFT 12U
>> #define ptes_per_page(page_size) ((page_size) / 8)
>> @@ -229,7 +240,7 @@ extern enum vm_guest_mode vm_mode_default;
>> #error "RISC-V 32-bit kvm selftests not supported"
>> #endif
>>
>> -#define VM_MODE_DEFAULT VM_MODE_P40V48_4K
>> +#define VM_MODE_DEFAULT vm_mode_default
>> #define MIN_PAGE_SHIFT 12U
>> #define ptes_per_page(page_size) ((page_size) / 8)
>>
>> diff --git a/tools/testing/selftests/kvm/include/riscv/processor.h b/tools/testing/selftests/kvm/include/riscv/processor.h
>> index 162f303d9daa..2d5a5548e698 100644
>> --- a/tools/testing/selftests/kvm/include/riscv/processor.h
>> +++ b/tools/testing/selftests/kvm/include/riscv/processor.h
>> @@ -191,4 +191,6 @@ static inline void local_irq_disable(void)
>> csr_clear(CSR_SSTATUS, SR_SIE);
>> }
>>
>> +unsigned long riscv64_get_satp_mode(void);
>> +
>> #endif /* SELFTEST_KVM_PROCESSOR_H */
>> diff --git a/tools/testing/selftests/kvm/lib/guest_modes.c b/tools/testing/selftests/kvm/lib/guest_modes.c
>> index b04901e55138..ce3099630397 100644
>> --- a/tools/testing/selftests/kvm/lib/guest_modes.c
>> +++ b/tools/testing/selftests/kvm/lib/guest_modes.c
>> @@ -4,7 +4,7 @@
>> */
>> #include "guest_modes.h"
>>
>> -#ifdef __aarch64__
>> +#if defined(__aarch64__) || defined(__riscv)
>> #include "processor.h"
>> enum vm_guest_mode vm_mode_default;
>> #endif
>> @@ -13,9 +13,11 @@ struct guest_mode guest_modes[NUM_VM_MODES];
>>
>> void guest_modes_append_default(void)
>> {
>> -#ifndef __aarch64__
>> +#if !defined(__aarch64__) && !defined(__riscv)
>> guest_mode_append(VM_MODE_DEFAULT, true);
>> -#else
>> +#endif
>> +
>> +#ifdef __aarch64__
>> {
>> unsigned int limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE);
>> uint32_t ipa4k, ipa16k, ipa64k;
>> @@ -74,11 +76,36 @@ void guest_modes_append_default(void)
>> #ifdef __riscv
>> {
>> unsigned int sz = kvm_check_cap(KVM_CAP_VM_GPA_BITS);
>> + unsigned long satp_mode = riscv64_get_satp_mode() << SATP_MODE_SHIFT;
>> + int i;
>>
>> - if (sz >= 52)
>> - guest_mode_append(VM_MODE_P52V48_4K, true);
>> - if (sz >= 48)
>> - guest_mode_append(VM_MODE_P48V48_4K, true);
>> + switch (sz) {
>> + case 59:
>> + guest_mode_append(VM_MODE_P56V57_4K, satp_mode >= SATP_MODE_57);
>> + guest_mode_append(VM_MODE_P56V48_4K, satp_mode >= SATP_MODE_48);
>> + guest_mode_append(VM_MODE_P56V39_4K, satp_mode >= SATP_MODE_39);
>> + break;
>> + case 50:
>> + guest_mode_append(VM_MODE_P50V57_4K, satp_mode >= SATP_MODE_57);
>> + guest_mode_append(VM_MODE_P50V48_4K, satp_mode >= SATP_MODE_48);
>> + guest_mode_append(VM_MODE_P50V39_4K, satp_mode >= SATP_MODE_39);
>> + break;
>> + case 41:
>> + guest_mode_append(VM_MODE_P41V57_4K, satp_mode >= SATP_MODE_57);
>> + guest_mode_append(VM_MODE_P41V48_4K, satp_mode >= SATP_MODE_48);
>> + guest_mode_append(VM_MODE_P41V39_4K, satp_mode >= SATP_MODE_39);
>> + break;
>> + default:
>> + break;
>> + }
>> +
>> + /* set the first supported mode as default */
>> + vm_mode_default = NUM_VM_MODES;
>> + for (i = 0; vm_mode_default == NUM_VM_MODES && i < NUM_VM_MODES; i++) {
>> + if (guest_modes[i].supported && guest_modes[i].enabled)
>> + vm_mode_default = i;
>> + }
>> + TEST_ASSERT(vm_mode_default != NUM_VM_MODES, "No supported mode!");
>> }
>> #endif
>> }
>> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
>> index a055343a7bf7..9803e61ae7db 100644
>> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
>> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
>> @@ -224,6 +224,15 @@ const char *vm_guest_mode_string(uint32_t i)
>> [VM_MODE_P36V48_64K] = "PA-bits:36, VA-bits:48, 64K pages",
>> [VM_MODE_P47V47_16K] = "PA-bits:47, VA-bits:47, 16K pages",
>> [VM_MODE_P36V47_16K] = "PA-bits:36, VA-bits:47, 16K pages",
>> + [VM_MODE_P56V57_4K] = "PA-bits:56, VA-bits:57, 4K pages",
>> + [VM_MODE_P56V48_4K] = "PA-bits:56, VA-bits:48, 4K pages",
>> + [VM_MODE_P56V39_4K] = "PA-bits:56, VA-bits:39, 4K pages",
>> + [VM_MODE_P50V57_4K] = "PA-bits:50, VA-bits:57, 4K pages",
>> + [VM_MODE_P50V48_4K] = "PA-bits:50, VA-bits:48, 4K pages",
>> + [VM_MODE_P50V39_4K] = "PA-bits:50, VA-bits:39, 4K pages",
>> + [VM_MODE_P41V57_4K] = "PA-bits:41, VA-bits:57, 4K pages",
>> + [VM_MODE_P41V48_4K] = "PA-bits:41, VA-bits:48, 4K pages",
>> + [VM_MODE_P41V39_4K] = "PA-bits:41, VA-bits:39, 4K pages",
>> };
>> _Static_assert(sizeof(strings)/sizeof(char *) == NUM_VM_MODES,
>> "Missing new mode strings?");
>> @@ -251,6 +260,15 @@ const struct vm_guest_mode_params vm_guest_mode_params[] = {
>> [VM_MODE_P36V48_64K] = { 36, 48, 0x10000, 16 },
>> [VM_MODE_P47V47_16K] = { 47, 47, 0x4000, 14 },
>> [VM_MODE_P36V47_16K] = { 36, 47, 0x4000, 14 },
>> + [VM_MODE_P56V57_4K] = { 56, 57, 0x1000, 12 },
>> + [VM_MODE_P56V48_4K] = { 56, 48, 0x1000, 12 },
>> + [VM_MODE_P56V39_4K] = { 56, 39, 0x1000, 12 },
>> + [VM_MODE_P50V57_4K] = { 50, 57, 0x1000, 12 },
>> + [VM_MODE_P50V48_4K] = { 50, 48, 0x1000, 12 },
>> + [VM_MODE_P50V39_4K] = { 50, 39, 0x1000, 12 },
>> + [VM_MODE_P41V57_4K] = { 41, 57, 0x1000, 12 },
>> + [VM_MODE_P41V48_4K] = { 41, 48, 0x1000, 12 },
>> + [VM_MODE_P41V39_4K] = { 41, 39, 0x1000, 12 },
>> };
>> _Static_assert(sizeof(vm_guest_mode_params)/sizeof(struct vm_guest_mode_params) == NUM_VM_MODES,
>> "Missing new mode params?");
>> @@ -351,6 +369,21 @@ struct kvm_vm *____vm_create(struct vm_shape shape)
>> case VM_MODE_P44V64_4K:
>> vm->pgtable_levels = 5;
>> break;
>> + case VM_MODE_P56V57_4K:
>> + case VM_MODE_P50V57_4K:
>> + case VM_MODE_P41V57_4K:
>> + vm->pgtable_levels = 5;
>> + break;
>> + case VM_MODE_P56V48_4K:
>> + case VM_MODE_P50V48_4K:
>> + case VM_MODE_P41V48_4K:
>> + vm->pgtable_levels = 4;
>> + break;
>> + case VM_MODE_P56V39_4K:
>> + case VM_MODE_P50V39_4K:
>> + case VM_MODE_P41V39_4K:
>> + vm->pgtable_levels = 3;
>> + break;
>> default:
>> TEST_FAIL("Unknown guest mode: 0x%x", vm->mode);
>> }
>> diff --git a/tools/testing/selftests/kvm/lib/riscv/processor.c b/tools/testing/selftests/kvm/lib/riscv/processor.c
>> index 2eac7d4b59e9..53675292b8eb 100644
>> --- a/tools/testing/selftests/kvm/lib/riscv/processor.c
>> +++ b/tools/testing/selftests/kvm/lib/riscv/processor.c
>> @@ -8,6 +8,7 @@
>> #include <linux/compiler.h>
>> #include <assert.h>
>>
>> +#include "guest_modes.h"
>> #include "kvm_util.h"
>> #include "processor.h"
>> #include "ucall_common.h"
>> @@ -197,22 +198,41 @@ void riscv_vcpu_mmu_setup(struct kvm_vcpu *vcpu)
>> {
>> struct kvm_vm *vm = vcpu->vm;
>> unsigned long satp;
>> + unsigned long satp_mode;
>> + unsigned long max_satp_mode;
>>
>> /*
>> * The RISC-V Sv48 MMU mode supports 56-bit physical address
>> * for 48-bit virtual address with 4KB last level page size.
>> */
>> switch (vm->mode) {
>> - case VM_MODE_P52V48_4K:
>> - case VM_MODE_P48V48_4K:
>> - case VM_MODE_P40V48_4K:
>> + case VM_MODE_P56V57_4K:
>> + case VM_MODE_P50V57_4K:
>> + case VM_MODE_P41V57_4K:
>> + satp_mode = SATP_MODE_57;
>> + break;
>> + case VM_MODE_P56V48_4K:
>> + case VM_MODE_P50V48_4K:
>> + case VM_MODE_P41V48_4K:
>> + satp_mode = SATP_MODE_48;
>> + break;
>> + case VM_MODE_P56V39_4K:
>> + case VM_MODE_P50V39_4K:
>> + case VM_MODE_P41V39_4K:
>> + satp_mode = SATP_MODE_39;
>> break;
>> default:
>> TEST_FAIL("Unknown guest mode, mode: 0x%x", vm->mode);
>> }
>>
>> + max_satp_mode = vcpu_get_reg(vcpu, RISCV_CONFIG_REG(satp_mode));
>> +
>> + if ((satp_mode >> SATP_MODE_SHIFT) > max_satp_mode)
>> + TEST_FAIL("Unable to set satp mode 0x%lx, max mode 0x%lx\n",
>> + satp_mode >> SATP_MODE_SHIFT, max_satp_mode);
>> +
>> satp = (vm->pgd >> PGTBL_PAGE_SIZE_SHIFT) & SATP_PPN;
>> - satp |= SATP_MODE_48;
>> + satp |= satp_mode;
>>
>> vcpu_set_reg(vcpu, RISCV_GENERAL_CSR_REG(satp), satp);
>> }
>> @@ -515,3 +535,38 @@ unsigned long get_host_sbi_spec_version(void)
>>
>> return ret.value;
>> }
>> +
>> +void kvm_selftest_arch_init(void)
>> +{
>> + /*
>> + * riscv64 doesn't have a true default mode, so start by detecting the
>> + * supported vm mode.
>> + */
>> + guest_modes_append_default();
>> +}
>> +
>> +unsigned long riscv64_get_satp_mode(void)
>> +{
>> + int kvm_fd, vm_fd, vcpu_fd, err;
>> + uint64_t val;
>> + struct kvm_one_reg reg = {
>> + .id = RISCV_CONFIG_REG(satp_mode),
>> + .addr = (uint64_t)&val,
>> + };
>> +
>> + kvm_fd = open_kvm_dev_path_or_exit();
>> + vm_fd = __kvm_ioctl(kvm_fd, KVM_CREATE_VM, NULL);
>> + TEST_ASSERT(vm_fd >= 0, KVM_IOCTL_ERROR(KVM_CREATE_VM, vm_fd));
>> +
>> + vcpu_fd = ioctl(vm_fd, KVM_CREATE_VCPU, 0);
>> + TEST_ASSERT(vcpu_fd >= 0, KVM_IOCTL_ERROR(KVM_CREATE_VCPU, vcpu_fd));
>> +
>> + err = ioctl(vcpu_fd, KVM_GET_ONE_REG, ®);
>> + TEST_ASSERT(err == 0, KVM_IOCTL_ERROR(KVM_GET_ONE_REG, vcpu_fd));
>> +
>> + close(vcpu_fd);
>> + close(vm_fd);
>> + close(kvm_fd);
>> +
>> + return val;
>> +}
>> --
>> 2.43.0
>>
>> --
>> kvm-riscv mailing list
>> kvm-riscv at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/kvm-riscv
>
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