[PATCH v2 RESEND] KVM: riscv: selftests: Add riscv vm satp modes
Wu Fei
atwufei at 163.com
Mon Dec 22 04:58:37 PST 2025
On 11/5/25 23:14, Wu Fei 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.
There is no new comment, how to move this forward?
Thanks,
Fei.
>
> Signed-off-by: Wu Fei <wu.fei9 at sanechips.com.cn>
> Reviewed-by: Andrew Jones <ajones at ventanamicro.com>
> Reviewed-by: Nutty Liu <nutty.liu at hotmail.com>
> Reviewed-by: Anup Patel <anup at brainfault.org>
> ---
> .../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 d3f3e455c031..c6d0b4a5b263 100644
> --- a/tools/testing/selftests/kvm/include/kvm_util.h
> +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> @@ -185,6 +185,17 @@ 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,
> };
>
> @@ -209,10 +220,10 @@ 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)
> @@ -235,7 +246,7 @@ 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 e58282488beb..4dade8c4d18e 100644
> --- a/tools/testing/selftests/kvm/include/riscv/processor.h
> +++ b/tools/testing/selftests/kvm/include/riscv/processor.h
> @@ -192,4 +192,6 @@ 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 1a93d6361671..a6a4bbc07211 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -209,6 +209,15 @@ 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?");
> @@ -236,6 +245,15 @@ 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?");
> @@ -336,6 +354,21 @@ 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..003693576225 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;
> +}
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