From: Quan Zhou <zhouquan@iscas.ac.cn>
Add support in KVM SBI FWFT extension to allow VS-mode to request
SBI_FWFT_{LANDING_PAD/SHADOW_STACK/PTE_AD_HW_UPDATING}.
Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn>
---
arch/riscv/include/uapi/asm/kvm.h | 3 +
arch/riscv/kvm/vcpu_sbi_fwft.c | 129 ++++++++++++++++++++++++++++++
2 files changed, 132 insertions(+)
diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h
index 7ca087848a43..d93b70d89010 100644
--- a/arch/riscv/include/uapi/asm/kvm.h
+++ b/arch/riscv/include/uapi/asm/kvm.h
@@ -232,6 +232,9 @@ struct kvm_riscv_sbi_fwft_feature {
struct kvm_riscv_sbi_fwft {
struct kvm_riscv_sbi_fwft_feature misaligned_deleg;
struct kvm_riscv_sbi_fwft_feature pointer_masking;
+ struct kvm_riscv_sbi_fwft_feature landing_pad;
+ struct kvm_riscv_sbi_fwft_feature shadow_stack;
+ struct kvm_riscv_sbi_fwft_feature pte_ad_hw_updating;
};
/* Possible states for kvm_riscv_timer */
diff --git a/arch/riscv/kvm/vcpu_sbi_fwft.c b/arch/riscv/kvm/vcpu_sbi_fwft.c
index 62cc9c3d5759..0dc0e70fc83b 100644
--- a/arch/riscv/kvm/vcpu_sbi_fwft.c
+++ b/arch/riscv/kvm/vcpu_sbi_fwft.c
@@ -213,6 +213,108 @@ static long kvm_sbi_fwft_get_pointer_masking_pmlen(struct kvm_vcpu *vcpu,
return SBI_SUCCESS;
}
+static long kvm_sbi_fwft_set_henvcfg_flag(struct kvm_vcpu *vcpu,
+ struct kvm_sbi_fwft_config *conf,
+ bool one_reg_access, unsigned long value,
+ unsigned long flag)
+{
+ struct kvm_vcpu_config *cfg = &vcpu->arch.cfg;
+
+ if (value == 1)
+ cfg->henvcfg |= flag;
+ else if (value == 0)
+ cfg->henvcfg &= ~flag;
+ else
+ return SBI_ERR_INVALID_PARAM;
+
+ if (!one_reg_access)
+ csr_write(CSR_HENVCFG, cfg->henvcfg);
+
+ return SBI_SUCCESS;
+}
+
+static bool kvm_sbi_fwft_pointer_landing_pad_supported(struct kvm_vcpu *vcpu)
+{
+ return riscv_isa_extension_available(vcpu->arch.isa, ZICFILP);
+}
+
+static void kvm_sbi_fwft_reset_landing_pad(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.cfg.henvcfg &= ~ENVCFG_LPE;
+}
+
+static long kvm_sbi_fwft_set_landing_pad(struct kvm_vcpu *vcpu,
+ struct kvm_sbi_fwft_config *conf,
+ bool one_reg_access, unsigned long value)
+{
+ return kvm_sbi_fwft_set_henvcfg_flag(vcpu, conf, one_reg_access, value, ENVCFG_LPE);
+}
+
+static long kvm_sbi_fwft_get_landing_pad(struct kvm_vcpu *vcpu,
+ struct kvm_sbi_fwft_config *conf,
+ bool one_reg_access, unsigned long *value)
+{
+ struct kvm_vcpu_config *cfg = &vcpu->arch.cfg;
+
+ *value = (cfg->henvcfg & ENVCFG_LPE) == ENVCFG_LPE;
+ return SBI_SUCCESS;
+}
+
+static bool kvm_sbi_fwft_pointer_shadow_stack_supported(struct kvm_vcpu *vcpu)
+{
+ return riscv_isa_extension_available(vcpu->arch.isa, ZICFISS);
+}
+
+static void kvm_sbi_fwft_reset_shadow_stack(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.cfg.henvcfg &= ~ENVCFG_SSE;
+}
+
+static long kvm_sbi_fwft_set_shadow_stack(struct kvm_vcpu *vcpu,
+ struct kvm_sbi_fwft_config *conf,
+ bool one_reg_access, unsigned long value)
+{
+ return kvm_sbi_fwft_set_henvcfg_flag(vcpu, conf, one_reg_access, value, ENVCFG_SSE);
+}
+
+static long kvm_sbi_fwft_get_shadow_stack(struct kvm_vcpu *vcpu,
+ struct kvm_sbi_fwft_config *conf,
+ bool one_reg_access, unsigned long *value)
+{
+ struct kvm_vcpu_config *cfg = &vcpu->arch.cfg;
+
+ *value = (cfg->henvcfg & ENVCFG_SSE) == ENVCFG_SSE;
+ return SBI_SUCCESS;
+}
+
+static bool kvm_sbi_fwft_pointer_pte_ad_hw_updating_supported(struct kvm_vcpu *vcpu)
+{
+ return riscv_isa_extension_available(vcpu->arch.isa, SVADU) &&
+ !riscv_isa_extension_available(vcpu->arch.isa, SVADE);
+}
+
+static void kvm_sbi_fwft_reset_pte_ad_hw_updating(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.cfg.henvcfg &= ~ENVCFG_ADUE;
+}
+
+static long kvm_sbi_fwft_set_pte_ad_hw_updating(struct kvm_vcpu *vcpu,
+ struct kvm_sbi_fwft_config *conf,
+ bool one_reg_access, unsigned long value)
+{
+ return kvm_sbi_fwft_set_henvcfg_flag(vcpu, conf, one_reg_access, value, ENVCFG_ADUE);
+}
+
+static long kvm_sbi_fwft_get_pte_ad_hw_updating(struct kvm_vcpu *vcpu,
+ struct kvm_sbi_fwft_config *conf,
+ bool one_reg_access, unsigned long *value)
+{
+ struct kvm_vcpu_config *cfg = &vcpu->arch.cfg;
+
+ *value = (cfg->henvcfg & ENVCFG_ADUE) == ENVCFG_ADUE;
+ return SBI_SUCCESS;
+}
+
#endif
static const struct kvm_sbi_fwft_feature features[] = {
@@ -236,6 +338,33 @@ static const struct kvm_sbi_fwft_feature features[] = {
.get = kvm_sbi_fwft_get_pointer_masking_pmlen,
},
#endif
+ {
+ .id = SBI_FWFT_LANDING_PAD,
+ .first_reg_num = offsetof(struct kvm_riscv_sbi_fwft, landing_pad.enable) /
+ sizeof(unsigned long),
+ .supported = kvm_sbi_fwft_landing_pad_supported,
+ .reset = kvm_sbi_fwft_reset_landing_pad,
+ .set = kvm_sbi_fwft_set_landing_pad,
+ .get = kvm_sbi_fwft_get_landing_pad,
+ },
+ {
+ .id = SBI_FWFT_SHADOW_STACK,
+ .first_reg_num = offsetof(struct kvm_riscv_sbi_fwft, shadow_stack.enable) /
+ sizeof(unsigned long),
+ .supported = kvm_sbi_fwft_shadow_stack_supported,
+ .reset = kvm_sbi_fwft_reset_shadow_stack,
+ .set = kvm_sbi_fwft_set_shadow_stack,
+ .get = kvm_sbi_fwft_get_shadow_stack,
+ },
+ {
+ .id = SBI_FWFT_PTE_AD_HW_UPDATING,
+ .first_reg_num = offsetof(struct kvm_riscv_sbi_fwft, pte_ad_hw_updating.enable) /
+ sizeof(unsigned long),
+ .supported = kvm_sbi_fwft_pte_ad_hw_updating_supported,
+ .reset = kvm_sbi_fwft_reset_pte_ad_hw_updating,
+ .set = kvm_sbi_fwft_set_pte_ad_hw_updating,
+ .get = kvm_sbi_fwft_get_pte_ad_hw_updating,
+ },
};
static const struct kvm_sbi_fwft_feature *kvm_sbi_fwft_regnum_to_feature(unsigned long reg_num)
--
2.34.1Hi,
kernel test robot noticed the following build errors:
[auto build test ERROR on kvm/queue]
[also build test ERROR on kvm/next linus/master v6.18 next-20251203]
[cannot apply to kvm/linux-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/zhouquan-iscas-ac-cn/RISC-V-KVM-Allow-zicfiss-zicfilp-exts-for-Guest-VM/20251201-094857
base: https://git.kernel.org/pub/scm/virt/kvm/kvm.git queue
patch link: https://lore.kernel.org/r/1793aa636969da0a09d27c9c12f6d5f8f0d1cd21.1764509485.git.zhouquan%40iscas.ac.cn
patch subject: [PATCH 3/4] RISC-V: KVM: Add suuport for zicfiss/zicfilp/svadu FWFT features
config: riscv-randconfig-001-20251203 (https://download.01.org/0day-ci/archive/20251203/202512031835.rfeAWiCJ-lkp@intel.com/config)
compiler: riscv32-linux-gcc (GCC) 14.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251203/202512031835.rfeAWiCJ-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512031835.rfeAWiCJ-lkp@intel.com/
All errors (new ones prefixed by >>):
>> arch/riscv/kvm/vcpu_sbi_fwft.c:345:30: error: 'kvm_sbi_fwft_landing_pad_supported' undeclared here (not in a function)
345 | .supported = kvm_sbi_fwft_landing_pad_supported,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> arch/riscv/kvm/vcpu_sbi_fwft.c:346:26: error: 'kvm_sbi_fwft_reset_landing_pad' undeclared here (not in a function)
346 | .reset = kvm_sbi_fwft_reset_landing_pad,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> arch/riscv/kvm/vcpu_sbi_fwft.c:347:24: error: 'kvm_sbi_fwft_set_landing_pad' undeclared here (not in a function)
347 | .set = kvm_sbi_fwft_set_landing_pad,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> arch/riscv/kvm/vcpu_sbi_fwft.c:348:24: error: 'kvm_sbi_fwft_get_landing_pad' undeclared here (not in a function)
348 | .get = kvm_sbi_fwft_get_landing_pad,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> arch/riscv/kvm/vcpu_sbi_fwft.c:354:30: error: 'kvm_sbi_fwft_shadow_stack_supported' undeclared here (not in a function)
354 | .supported = kvm_sbi_fwft_shadow_stack_supported,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> arch/riscv/kvm/vcpu_sbi_fwft.c:355:26: error: 'kvm_sbi_fwft_reset_shadow_stack' undeclared here (not in a function)
355 | .reset = kvm_sbi_fwft_reset_shadow_stack,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> arch/riscv/kvm/vcpu_sbi_fwft.c:356:24: error: 'kvm_sbi_fwft_set_shadow_stack' undeclared here (not in a function)
356 | .set = kvm_sbi_fwft_set_shadow_stack,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> arch/riscv/kvm/vcpu_sbi_fwft.c:357:24: error: 'kvm_sbi_fwft_get_shadow_stack' undeclared here (not in a function)
357 | .get = kvm_sbi_fwft_get_shadow_stack,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> arch/riscv/kvm/vcpu_sbi_fwft.c:363:30: error: 'kvm_sbi_fwft_pte_ad_hw_updating_supported' undeclared here (not in a function)
363 | .supported = kvm_sbi_fwft_pte_ad_hw_updating_supported,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> arch/riscv/kvm/vcpu_sbi_fwft.c:364:26: error: 'kvm_sbi_fwft_reset_pte_ad_hw_updating' undeclared here (not in a function)
364 | .reset = kvm_sbi_fwft_reset_pte_ad_hw_updating,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> arch/riscv/kvm/vcpu_sbi_fwft.c:365:24: error: 'kvm_sbi_fwft_set_pte_ad_hw_updating' undeclared here (not in a function)
365 | .set = kvm_sbi_fwft_set_pte_ad_hw_updating,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> arch/riscv/kvm/vcpu_sbi_fwft.c:366:24: error: 'kvm_sbi_fwft_get_pte_ad_hw_updating' undeclared here (not in a function)
366 | .get = kvm_sbi_fwft_get_pte_ad_hw_updating,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
vim +/kvm_sbi_fwft_landing_pad_supported +345 arch/riscv/kvm/vcpu_sbi_fwft.c
319
320 static const struct kvm_sbi_fwft_feature features[] = {
321 {
322 .id = SBI_FWFT_MISALIGNED_EXC_DELEG,
323 .first_reg_num = offsetof(struct kvm_riscv_sbi_fwft, misaligned_deleg.enable) /
324 sizeof(unsigned long),
325 .supported = kvm_sbi_fwft_misaligned_delegation_supported,
326 .reset = kvm_sbi_fwft_reset_misaligned_delegation,
327 .set = kvm_sbi_fwft_set_misaligned_delegation,
328 .get = kvm_sbi_fwft_get_misaligned_delegation,
329 },
330 #ifndef CONFIG_32BIT
331 {
332 .id = SBI_FWFT_POINTER_MASKING_PMLEN,
333 .first_reg_num = offsetof(struct kvm_riscv_sbi_fwft, pointer_masking.enable) /
334 sizeof(unsigned long),
335 .supported = kvm_sbi_fwft_pointer_masking_pmlen_supported,
336 .reset = kvm_sbi_fwft_reset_pointer_masking_pmlen,
337 .set = kvm_sbi_fwft_set_pointer_masking_pmlen,
338 .get = kvm_sbi_fwft_get_pointer_masking_pmlen,
339 },
340 #endif
341 {
342 .id = SBI_FWFT_LANDING_PAD,
343 .first_reg_num = offsetof(struct kvm_riscv_sbi_fwft, landing_pad.enable) /
344 sizeof(unsigned long),
> 345 .supported = kvm_sbi_fwft_landing_pad_supported,
> 346 .reset = kvm_sbi_fwft_reset_landing_pad,
> 347 .set = kvm_sbi_fwft_set_landing_pad,
> 348 .get = kvm_sbi_fwft_get_landing_pad,
349 },
350 {
351 .id = SBI_FWFT_SHADOW_STACK,
352 .first_reg_num = offsetof(struct kvm_riscv_sbi_fwft, shadow_stack.enable) /
353 sizeof(unsigned long),
> 354 .supported = kvm_sbi_fwft_shadow_stack_supported,
> 355 .reset = kvm_sbi_fwft_reset_shadow_stack,
> 356 .set = kvm_sbi_fwft_set_shadow_stack,
> 357 .get = kvm_sbi_fwft_get_shadow_stack,
358 },
359 {
360 .id = SBI_FWFT_PTE_AD_HW_UPDATING,
361 .first_reg_num = offsetof(struct kvm_riscv_sbi_fwft, pte_ad_hw_updating.enable) /
362 sizeof(unsigned long),
> 363 .supported = kvm_sbi_fwft_pte_ad_hw_updating_supported,
> 364 .reset = kvm_sbi_fwft_reset_pte_ad_hw_updating,
> 365 .set = kvm_sbi_fwft_set_pte_ad_hw_updating,
> 366 .get = kvm_sbi_fwft_get_pte_ad_hw_updating,
367 },
368 };
369
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
© 2016 - 2026 Red Hat, Inc.