From 94a7734d0967e89fac5be1fd5115f5194e4a4017 Mon Sep 17 00:00:00 2001 From: Yong-Xuan Wang Date: Fri, 26 Jul 2024 16:49:26 +0800 Subject: [PATCH 1/4] RISC-V: Add Svade and Svadu Extensions Support Svade and Svadu extensions represent two schemes for managing the PTE A/D bits. When the PTE A/D bits need to be set, Svade extension intdicates that a related page fault will be raised. In contrast, the Svadu extension supports hardware updating of PTE A/D bits. Since the Svade extension is mandatory and the Svadu extension is optional in RVA23 profile, by default the M-mode firmware will enable the Svadu extension in the menvcfg CSR when only Svadu is present in DT. This patch detects Svade and Svadu extensions from DT and adds arch_has_hw_pte_young() to enable optimization in MGLRU and __wp_page_copy_user() when we have the PTE A/D bits hardware updating support. Co-developed-by: Jinyu Tang Signed-off-by: Jinyu Tang Signed-off-by: Yong-Xuan Wang Reviewed-by: Andrew Jones Reviewed-by: Alexandre Ghiti Acked-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20240726084931.28924-2-yongxuan.wang@sifive.com Signed-off-by: Anup Patel --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/csr.h | 1 + arch/riscv/include/asm/hwcap.h | 2 ++ arch/riscv/include/asm/pgtable.h | 13 ++++++++++++- arch/riscv/kernel/cpufeature.c | 12 ++++++++++++ 5 files changed, 28 insertions(+), 1 deletion(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 62545946ecf432..2e499918e15ea7 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -32,6 +32,7 @@ config RISCV select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_GCOV_PROFILE_ALL select ARCH_HAS_GIGANTIC_PAGE + select ARCH_HAS_HW_PTE_YOUNG select ARCH_HAS_KCOV select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU select ARCH_HAS_MEMBARRIER_CALLBACKS diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h index 25966995da04e0..524cd4131c713d 100644 --- a/arch/riscv/include/asm/csr.h +++ b/arch/riscv/include/asm/csr.h @@ -195,6 +195,7 @@ /* xENVCFG flags */ #define ENVCFG_STCE (_AC(1, ULL) << 63) #define ENVCFG_PBMTE (_AC(1, ULL) << 62) +#define ENVCFG_ADUE (_AC(1, ULL) << 61) #define ENVCFG_CBZE (_AC(1, UL) << 7) #define ENVCFG_CBCFE (_AC(1, UL) << 6) #define ENVCFG_CBIE_SHIFT 4 diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index 46d9de54179ed4..7f72789ba3d5da 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -93,6 +93,8 @@ #define RISCV_ISA_EXT_ZCMOP 84 #define RISCV_ISA_EXT_ZAWRS 85 #define RISCV_ISA_EXT_SVVPTC 86 +#define RISCV_ISA_EXT_SVADE 87 +#define RISCV_ISA_EXT_SVADU 88 #define RISCV_ISA_EXT_XLINUXENVCFG 127 diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index e79f15293492d5..02aa7ee6def8b0 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -113,6 +113,7 @@ #include #include #include +#include #define __page_val_to_pfn(_val) (((_val) & _PAGE_PFN_MASK) >> _PAGE_PFN_SHIFT) @@ -284,7 +285,6 @@ static inline pte_t pud_pte(pud_t pud) } #ifdef CONFIG_RISCV_ISA_SVNAPOT -#include static __always_inline bool has_svnapot(void) { @@ -655,6 +655,17 @@ static inline pgprot_t pgprot_writecombine(pgprot_t _prot) return __pgprot(prot); } +/* + * Both Svade and Svadu control the hardware behavior when the PTE A/D bits need to be set. By + * default the M-mode firmware enables the hardware updating scheme when only Svadu is present in + * DT. + */ +#define arch_has_hw_pte_young arch_has_hw_pte_young +static inline bool arch_has_hw_pte_young(void) +{ + return riscv_has_extension_unlikely(RISCV_ISA_EXT_SVADU); +} + /* * THP functions */ diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 3a8eeaa9310c32..06ca264d481012 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -132,6 +132,16 @@ static int riscv_ext_zcf_validate(const struct riscv_isa_ext_data *data, return -EPROBE_DEFER; } +static int riscv_ext_svadu_validate(const struct riscv_isa_ext_data *data, + const unsigned long *isa_bitmap) +{ + /* SVADE has already been detected, use SVADE only */ + if (__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_SVADE)) + return -EOPNOTSUPP; + + return 0; +} + static const unsigned int riscv_zk_bundled_exts[] = { RISCV_ISA_EXT_ZBKB, RISCV_ISA_EXT_ZBKC, @@ -378,6 +388,8 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = { __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA), __RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF), __RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC), + __RISCV_ISA_EXT_DATA(svade, RISCV_ISA_EXT_SVADE), + __RISCV_ISA_EXT_DATA_VALIDATE(svadu, RISCV_ISA_EXT_SVADU, riscv_ext_svadu_validate), __RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL), __RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT), __RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT), From b8d481671703c4ba24bb250a99225e0e3d8aedac Mon Sep 17 00:00:00 2001 From: Yong-Xuan Wang Date: Fri, 26 Jul 2024 16:49:27 +0800 Subject: [PATCH 2/4] dt-bindings: riscv: Add Svade and Svadu Entries Add entries for the Svade and Svadu extensions to the riscv,isa-extensions property. Signed-off-by: Yong-Xuan Wang Acked-by: Conor Dooley Reviewed-by: Alexandre Ghiti Reviewed-by: Samuel Holland Acked-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20240726084931.28924-3-yongxuan.wang@sifive.com Signed-off-by: Anup Patel --- .../devicetree/bindings/riscv/extensions.yaml | 28 +++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml index 2cf2026cff574d..c5a8d154bb24e1 100644 --- a/Documentation/devicetree/bindings/riscv/extensions.yaml +++ b/Documentation/devicetree/bindings/riscv/extensions.yaml @@ -153,6 +153,34 @@ properties: ratified at commit 3f9ed34 ("Add ability to manually trigger workflow. (#2)") of riscv-time-compare. + - const: svade + description: | + The standard Svade supervisor-level extension for SW-managed PTE A/D + bit updates as ratified in the 20240213 version of the privileged + ISA specification. + + Both Svade and Svadu extensions control the hardware behavior when + the PTE A/D bits need to be set. The default behavior for the four + possible combinations of these extensions in the device tree are: + 1) Neither Svade nor Svadu present in DT => It is technically + unknown whether the platform uses Svade or Svadu. Supervisor + software should be prepared to handle either hardware updating + of the PTE A/D bits or page faults when they need updated. + 2) Only Svade present in DT => Supervisor must assume Svade to be + always enabled. + 3) Only Svadu present in DT => Supervisor must assume Svadu to be + always enabled. + 4) Both Svade and Svadu present in DT => Supervisor must assume + Svadu turned-off at boot time. To use Svadu, supervisor must + explicitly enable it using the SBI FWFT extension. + + - const: svadu + description: | + The standard Svadu supervisor-level extension for hardware updating + of PTE A/D bits as ratified in the 20240528 version of the + privileged ISA specification. Please refer to Svade dt-binding + description for more details. + - const: svinval description: The standard Svinval supervisor-level extension for fine-grained From 97eccf7db4f2e5e59d16bca45f7803ae3aeff6e1 Mon Sep 17 00:00:00 2001 From: Yong-Xuan Wang Date: Fri, 26 Jul 2024 16:49:28 +0800 Subject: [PATCH 3/4] RISC-V: KVM: Add Svade and Svadu Extensions Support for Guest/VM We extend the KVM ISA extension ONE_REG interface to allow VMM tools to detect and enable Svade and Svadu extensions for Guest/VM. Since the henvcfg.ADUE is read-only zero if the menvcfg.ADUE is zero, the Svadu extension is available for Guest/VM and the Svade extension is allowed to disabledonly when arch_has_hw_pte_young() is true. Signed-off-by: Yong-Xuan Wang Reviewed-by: Andrew Jones Reviewed-by: Samuel Holland Acked-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20240726084931.28924-4-yongxuan.wang@sifive.com Signed-off-by: Anup Patel --- arch/riscv/include/uapi/asm/kvm.h | 2 ++ arch/riscv/kvm/vcpu.c | 4 ++++ arch/riscv/kvm/vcpu_onereg.c | 15 +++++++++++++++ 3 files changed, 21 insertions(+) diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h index e97db3296456e1..85bbc472989dff 100644 --- a/arch/riscv/include/uapi/asm/kvm.h +++ b/arch/riscv/include/uapi/asm/kvm.h @@ -175,6 +175,8 @@ enum KVM_RISCV_ISA_EXT_ID { KVM_RISCV_ISA_EXT_ZCF, KVM_RISCV_ISA_EXT_ZCMOP, KVM_RISCV_ISA_EXT_ZAWRS, + KVM_RISCV_ISA_EXT_SVADE, + KVM_RISCV_ISA_EXT_SVADU, KVM_RISCV_ISA_EXT_MAX, }; diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index dc3f76f6e46cea..e048dcc6e65e73 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -551,6 +551,10 @@ static void kvm_riscv_vcpu_setup_config(struct kvm_vcpu *vcpu) if (riscv_isa_extension_available(isa, ZICBOZ)) cfg->henvcfg |= ENVCFG_CBZE; + if (riscv_isa_extension_available(isa, SVADU) && + !riscv_isa_extension_available(isa, SVADE)) + cfg->henvcfg |= ENVCFG_ADUE; + if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN)) { cfg->hstateen0 |= SMSTATEEN0_HSENVCFG; if (riscv_isa_extension_available(isa, SSAIA)) diff --git a/arch/riscv/kvm/vcpu_onereg.c b/arch/riscv/kvm/vcpu_onereg.c index b319c4c13c54ce..b3f58908902a74 100644 --- a/arch/riscv/kvm/vcpu_onereg.c +++ b/arch/riscv/kvm/vcpu_onereg.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #define KVM_RISCV_BASE_ISA_MASK GENMASK(25, 0) @@ -38,6 +39,8 @@ static const unsigned long kvm_isa_ext_arr[] = { KVM_ISA_EXT_ARR(SSAIA), KVM_ISA_EXT_ARR(SSCOFPMF), KVM_ISA_EXT_ARR(SSTC), + KVM_ISA_EXT_ARR(SVADE), + KVM_ISA_EXT_ARR(SVADU), KVM_ISA_EXT_ARR(SVINVAL), KVM_ISA_EXT_ARR(SVNAPOT), KVM_ISA_EXT_ARR(SVPBMT), @@ -110,6 +113,12 @@ static bool kvm_riscv_vcpu_isa_enable_allowed(unsigned long ext) case KVM_RISCV_ISA_EXT_SSCOFPMF: /* Sscofpmf depends on interrupt filtering defined in ssaia */ return __riscv_isa_extension_available(NULL, RISCV_ISA_EXT_SSAIA); + case KVM_RISCV_ISA_EXT_SVADU: + /* + * The henvcfg.ADUE is read-only zero if menvcfg.ADUE is zero. + * Guest OS can use Svadu only when host OS enable Svadu. + */ + return arch_has_hw_pte_young(); case KVM_RISCV_ISA_EXT_V: return riscv_v_vstate_ctrl_user_allowed(); default: @@ -181,6 +190,12 @@ static bool kvm_riscv_vcpu_isa_disable_allowed(unsigned long ext) /* Extensions which can be disabled using Smstateen */ case KVM_RISCV_ISA_EXT_SSAIA: return riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN); + case KVM_RISCV_ISA_EXT_SVADE: + /* + * The henvcfg.ADUE is read-only zero if menvcfg.ADUE is zero. + * Svade is not allowed to disable when the platform use Svade. + */ + return arch_has_hw_pte_young(); default: break; } From c74bfe4ffe8c1ca94e3d60ec7af06cf679e23583 Mon Sep 17 00:00:00 2001 From: Yong-Xuan Wang Date: Fri, 26 Jul 2024 16:49:30 +0800 Subject: [PATCH 4/4] KVM: riscv: selftests: Add Svade and Svadu Extension to get-reg-list test Update the get-reg-list test to test the Svade and Svadu Extensions are available for guest OS. Signed-off-by: Yong-Xuan Wang Reviewed-by: Andrew Jones Acked-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20240726084931.28924-6-yongxuan.wang@sifive.com Signed-off-by: Anup Patel --- tools/testing/selftests/kvm/riscv/get-reg-list.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/tools/testing/selftests/kvm/riscv/get-reg-list.c b/tools/testing/selftests/kvm/riscv/get-reg-list.c index 8e34f7fa44e94c..aac40652e18173 100644 --- a/tools/testing/selftests/kvm/riscv/get-reg-list.c +++ b/tools/testing/selftests/kvm/riscv/get-reg-list.c @@ -45,6 +45,8 @@ bool filter_reg(__u64 reg) case KVM_REG_RISCV_ISA_EXT | KVM_REG_RISCV_ISA_SINGLE | KVM_RISCV_ISA_EXT_SSAIA: case KVM_REG_RISCV_ISA_EXT | KVM_REG_RISCV_ISA_SINGLE | KVM_RISCV_ISA_EXT_SSCOFPMF: case KVM_REG_RISCV_ISA_EXT | KVM_REG_RISCV_ISA_SINGLE | KVM_RISCV_ISA_EXT_SSTC: + case KVM_REG_RISCV_ISA_EXT | KVM_REG_RISCV_ISA_SINGLE | KVM_RISCV_ISA_EXT_SVADE: + case KVM_REG_RISCV_ISA_EXT | KVM_REG_RISCV_ISA_SINGLE | KVM_RISCV_ISA_EXT_SVADU: case KVM_REG_RISCV_ISA_EXT | KVM_REG_RISCV_ISA_SINGLE | KVM_RISCV_ISA_EXT_SVINVAL: case KVM_REG_RISCV_ISA_EXT | KVM_REG_RISCV_ISA_SINGLE | KVM_RISCV_ISA_EXT_SVNAPOT: case KVM_REG_RISCV_ISA_EXT | KVM_REG_RISCV_ISA_SINGLE | KVM_RISCV_ISA_EXT_SVPBMT: @@ -418,6 +420,8 @@ static const char *isa_ext_single_id_to_str(__u64 reg_off) KVM_ISA_EXT_ARR(SSAIA), KVM_ISA_EXT_ARR(SSCOFPMF), KVM_ISA_EXT_ARR(SSTC), + KVM_ISA_EXT_ARR(SVADE), + KVM_ISA_EXT_ARR(SVADU), KVM_ISA_EXT_ARR(SVINVAL), KVM_ISA_EXT_ARR(SVNAPOT), KVM_ISA_EXT_ARR(SVPBMT), @@ -949,6 +953,8 @@ KVM_ISA_EXT_SIMPLE_CONFIG(h, H); KVM_ISA_EXT_SUBLIST_CONFIG(smstateen, SMSTATEEN); KVM_ISA_EXT_SIMPLE_CONFIG(sscofpmf, SSCOFPMF); KVM_ISA_EXT_SIMPLE_CONFIG(sstc, SSTC); +KVM_ISA_EXT_SIMPLE_CONFIG(svade, SVADE); +KVM_ISA_EXT_SIMPLE_CONFIG(svadu, SVADU); KVM_ISA_EXT_SIMPLE_CONFIG(svinval, SVINVAL); KVM_ISA_EXT_SIMPLE_CONFIG(svnapot, SVNAPOT); KVM_ISA_EXT_SIMPLE_CONFIG(svpbmt, SVPBMT); @@ -1012,6 +1018,8 @@ struct vcpu_reg_list *vcpu_configs[] = { &config_smstateen, &config_sscofpmf, &config_sstc, + &config_svade, + &config_svadu, &config_svinval, &config_svnapot, &config_svpbmt,