From 2bfc654b89c4dd1c372bb2cbba6b5a0eb578d214 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 9 Nov 2023 15:47:49 +0000 Subject: [PATCH 01/10] arm64: cpufeatures: Restrict NV support to FEAT_NV2 To anyone who has played with FEAT_NV, it is obvious that the level of performance is rather low due to the trap amplification that it imposes on the host hypervisor. FEAT_NV2 solves a number of the problems that FEAT_NV had. It also turns out that all the existing hardware that has FEAT_NV also has FEAT_NV2. Finally, it is now allowed by the architecture to build FEAT_NV2 *only* (as denoted by ID_AA64MMFR4_EL1.NV_frac), which effectively seals the fate of FEAT_NV. Restrict the NV support to NV2, and be done with it. Nobody will cry over the old crap. NV_frac will eventually be supported once the intrastructure is ready. Reviewed-by: Oliver Upton Signed-off-by: Marc Zyngier --- arch/arm64/kernel/cpufeature.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 646591c67e7a..1329e974d187 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2339,7 +2339,7 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .capability = ARM64_HAS_NESTED_VIRT, .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_nested_virt_support, - ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, NV, IMP) + ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, NV, NV2) }, { .capability = ARM64_HAS_32BIT_EL0_DO_NOT_USE, From 111903d1f5b9334d1100e1c6ee08e740fa374d91 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 13 Nov 2023 14:16:02 +0000 Subject: [PATCH 02/10] KVM: arm64: nv: Hoist vcpu_has_nv() into is_hyp_ctxt() A rather common idiom when writing NV code as part of KVM is to have things such has: if (vcpu_has_nv(vcpu) && is_hyp_ctxt(vcpu)) { [...] } to check that we are in a hyp-related context. The second part of the conjunction would be enough, but the first one contains a static key that allows the rest of the checkis to be elided when in a non-NV environment. Rewrite is_hyp_ctxt() to directly use vcpu_has_nv(). The result is the same, and the code easier to read. The one occurence of this that is already merged is rewritten in the process. In order to avoid nasty cirtular dependencies between kvm_emulate.h and kvm_nested.h, vcpu_has_feature() is itself hoisted into kvm_host.h, at the cost of some #deferry... Reviewed-by: Oliver Upton Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_emulate.h | 8 ++------ arch/arm64/include/asm/kvm_host.h | 7 +++++++ arch/arm64/kvm/arch_timer.c | 3 +-- 3 files changed, 10 insertions(+), 8 deletions(-) diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index 78a550537b67..84829b7e6f1d 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -54,11 +55,6 @@ void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu); int kvm_inject_nested_sync(struct kvm_vcpu *vcpu, u64 esr_el2); int kvm_inject_nested_irq(struct kvm_vcpu *vcpu); -static inline bool vcpu_has_feature(const struct kvm_vcpu *vcpu, int feature) -{ - return test_bit(feature, vcpu->kvm->arch.vcpu_features); -} - #if defined(__KVM_VHE_HYPERVISOR__) || defined(__KVM_NVHE_HYPERVISOR__) static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu) { @@ -248,7 +244,7 @@ static inline bool __is_hyp_ctxt(const struct kvm_cpu_context *ctxt) static inline bool is_hyp_ctxt(const struct kvm_vcpu *vcpu) { - return __is_hyp_ctxt(&vcpu->arch.ctxt); + return vcpu_has_nv(vcpu) && __is_hyp_ctxt(&vcpu->arch.ctxt); } /* diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 824f29f04916..4103a12ecaaf 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1177,6 +1177,13 @@ bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu); #define kvm_vm_has_ran_once(kvm) \ (test_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &(kvm)->arch.flags)) +static inline bool __vcpu_has_feature(const struct kvm_arch *ka, int feature) +{ + return test_bit(feature, ka->vcpu_features); +} + +#define vcpu_has_feature(v, f) __vcpu_has_feature(&(v)->kvm->arch, (f)) + int kvm_trng_call(struct kvm_vcpu *vcpu); #ifdef CONFIG_KVM extern phys_addr_t hyp_mem_base; diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c index 13ba691b848f..9dec8c419bf4 100644 --- a/arch/arm64/kvm/arch_timer.c +++ b/arch/arm64/kvm/arch_timer.c @@ -295,8 +295,7 @@ static u64 wfit_delay_ns(struct kvm_vcpu *vcpu) u64 val = vcpu_get_reg(vcpu, kvm_vcpu_sys_get_rt(vcpu)); struct arch_timer_context *ctx; - ctx = (vcpu_has_nv(vcpu) && is_hyp_ctxt(vcpu)) ? vcpu_hvtimer(vcpu) - : vcpu_vtimer(vcpu); + ctx = is_hyp_ctxt(vcpu) ? vcpu_hvtimer(vcpu) : vcpu_vtimer(vcpu); return kvm_counter_compute_delta(ctx, val); } From 3ed0b5123cd5a2a4f1fe4e594e7bf319e9eaf1da Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Sun, 12 Nov 2023 21:05:14 +0000 Subject: [PATCH 03/10] KVM: arm64: nv: Compute NV view of idregs as a one-off Now that we have a full copy of the idregs for each VM, there is no point in repainting the sysregs on each access. Instead, we can simply perform the transmation as a one-off and be done with it. Reviewed-by: Oliver Upton Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/include/asm/kvm_nested.h | 6 +----- arch/arm64/kvm/arm.c | 6 ++++++ arch/arm64/kvm/nested.c | 22 +++++++++++++++------- arch/arm64/kvm/sys_regs.c | 2 -- 5 files changed, 23 insertions(+), 14 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 4103a12ecaaf..fce2e5f583a7 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -306,6 +306,7 @@ struct kvm_arch { * Atomic access to multiple idregs are guarded by kvm_arch.config_lock. */ #define IDREG_IDX(id) (((sys_reg_CRm(id) - 1) << 3) | sys_reg_Op2(id)) +#define IDX_IDREG(idx) sys_reg(3, 0, 0, ((idx) >> 3) + 1, (idx) & Op2_mask) #define IDREG(kvm, id) ((kvm)->arch.id_regs[IDREG_IDX(id)]) #define KVM_ARM_ID_REG_NUM (IDREG_IDX(sys_reg(3, 0, 0, 7, 7)) + 1) u64 id_regs[KVM_ARM_ID_REG_NUM]; diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index 6cec8e9c6c91..249b03fc2cce 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -14,10 +14,6 @@ static inline bool vcpu_has_nv(const struct kvm_vcpu *vcpu) extern bool __check_nv_sr_forward(struct kvm_vcpu *vcpu); -struct sys_reg_params; -struct sys_reg_desc; - -void access_nested_id_reg(struct kvm_vcpu *v, struct sys_reg_params *p, - const struct sys_reg_desc *r); +int kvm_init_nv_sysregs(struct kvm *kvm); #endif /* __ARM64_KVM_NESTED_H */ diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index e5f75f1f1085..b65df612b41b 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -669,6 +669,12 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu) return ret; } + if (vcpu_has_nv(vcpu)) { + ret = kvm_init_nv_sysregs(vcpu->kvm); + if (ret) + return ret; + } + ret = kvm_timer_enable(vcpu); if (ret) return ret; diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index 042695a210ce..ba95d044bc98 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -23,13 +23,9 @@ * This list should get updated as new features get added to the NV * support, and new extension to the architecture. */ -void access_nested_id_reg(struct kvm_vcpu *v, struct sys_reg_params *p, - const struct sys_reg_desc *r) +static u64 limit_nv_id_reg(u32 id, u64 val) { - u32 id = reg_to_encoding(r); - u64 val, tmp; - - val = p->regval; + u64 tmp; switch (id) { case SYS_ID_AA64ISAR0_EL1: @@ -158,5 +154,17 @@ void access_nested_id_reg(struct kvm_vcpu *v, struct sys_reg_params *p, break; } - p->regval = val; + return val; +} +int kvm_init_nv_sysregs(struct kvm *kvm) +{ + mutex_lock(&kvm->arch.config_lock); + + for (int i = 0; i < KVM_ARM_ID_REG_NUM; i++) + kvm->arch.id_regs[i] = limit_nv_id_reg(IDX_IDREG(i), + kvm->arch.id_regs[i]); + + mutex_unlock(&kvm->arch.config_lock); + + return 0; } diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 4735e1b37fb3..3eae84195d48 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1505,8 +1505,6 @@ static bool access_id_reg(struct kvm_vcpu *vcpu, return write_to_read_only(vcpu, p, r); p->regval = read_id_reg(vcpu, r); - if (vcpu_has_nv(vcpu)) - access_nested_id_reg(vcpu, p, r); return true; } From 4d4f52052ba8357f1591cb9bc3086541070711af Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 8 Nov 2023 19:10:12 +0000 Subject: [PATCH 04/10] KVM: arm64: nv: Drop EL12 register traps that are redirected to VNCR With FEAT_NV2, a bunch of system register writes are turned into memory writes. This is specially the fate of the EL12 registers that the guest hypervisor manipulates out of context. Remove the trap descriptors for those, as they are never going to be used again. Reviewed-by: Oliver Upton Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 15 --------------- 1 file changed, 15 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 3eae84195d48..cdfc79ccc7a1 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2566,21 +2566,6 @@ static const struct sys_reg_desc sys_reg_descs[] = { EL2_REG(CNTVOFF_EL2, access_rw, reset_val, 0), EL2_REG(CNTHCTL_EL2, access_rw, reset_val, 0), - EL12_REG(SCTLR, access_vm_reg, reset_val, 0x00C50078), - EL12_REG(CPACR, access_rw, reset_val, 0), - EL12_REG(TTBR0, access_vm_reg, reset_unknown, 0), - EL12_REG(TTBR1, access_vm_reg, reset_unknown, 0), - EL12_REG(TCR, access_vm_reg, reset_val, 0), - { SYS_DESC(SYS_SPSR_EL12), access_spsr}, - { SYS_DESC(SYS_ELR_EL12), access_elr}, - EL12_REG(AFSR0, access_vm_reg, reset_unknown, 0), - EL12_REG(AFSR1, access_vm_reg, reset_unknown, 0), - EL12_REG(ESR, access_vm_reg, reset_unknown, 0), - EL12_REG(FAR, access_vm_reg, reset_unknown, 0), - EL12_REG(MAIR, access_vm_reg, reset_unknown, 0), - EL12_REG(AMAIR, access_vm_reg, reset_amair_el1, 0), - EL12_REG(VBAR, access_rw, reset_val, 0), - EL12_REG(CONTEXTIDR, access_vm_reg, reset_val, 0), EL12_REG(CNTKCTL, access_rw, reset_val, 0), EL2_REG(SP_EL2, NULL, reset_unknown, 0), From 3606e0b2e462164bced151dbb54ccfe42ac6c35b Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Sun, 25 Dec 2016 10:49:48 -0500 Subject: [PATCH 05/10] KVM: arm64: nv: Add non-VHE-EL2->EL1 translation helpers Some EL2 system registers immediately affect the current execution of the system, so we need to use their respective EL1 counterparts. For this we need to define a mapping between the two. In general, this only affects non-VHE guest hypervisors, as VHE system registers are compatible with the EL1 counterparts. These helpers will get used in subsequent patches. Reviewed-by: Oliver Upton Co-developed-by: Andre Przywara Signed-off-by: Andre Przywara Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_nested.h | 50 ++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index 249b03fc2cce..4882905357f4 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -2,8 +2,9 @@ #ifndef __ARM64_KVM_NESTED_H #define __ARM64_KVM_NESTED_H -#include +#include #include +#include static inline bool vcpu_has_nv(const struct kvm_vcpu *vcpu) { @@ -12,6 +13,53 @@ static inline bool vcpu_has_nv(const struct kvm_vcpu *vcpu) vcpu_has_feature(vcpu, KVM_ARM_VCPU_HAS_EL2)); } +/* Translation helpers from non-VHE EL2 to EL1 */ +static inline u64 tcr_el2_ps_to_tcr_el1_ips(u64 tcr_el2) +{ + return (u64)FIELD_GET(TCR_EL2_PS_MASK, tcr_el2) << TCR_IPS_SHIFT; +} + +static inline u64 translate_tcr_el2_to_tcr_el1(u64 tcr) +{ + return TCR_EPD1_MASK | /* disable TTBR1_EL1 */ + ((tcr & TCR_EL2_TBI) ? TCR_TBI0 : 0) | + tcr_el2_ps_to_tcr_el1_ips(tcr) | + (tcr & TCR_EL2_TG0_MASK) | + (tcr & TCR_EL2_ORGN0_MASK) | + (tcr & TCR_EL2_IRGN0_MASK) | + (tcr & TCR_EL2_T0SZ_MASK); +} + +static inline u64 translate_cptr_el2_to_cpacr_el1(u64 cptr_el2) +{ + u64 cpacr_el1 = 0; + + if (cptr_el2 & CPTR_EL2_TTA) + cpacr_el1 |= CPACR_ELx_TTA; + if (!(cptr_el2 & CPTR_EL2_TFP)) + cpacr_el1 |= CPACR_ELx_FPEN; + if (!(cptr_el2 & CPTR_EL2_TZ)) + cpacr_el1 |= CPACR_ELx_ZEN; + + return cpacr_el1; +} + +static inline u64 translate_sctlr_el2_to_sctlr_el1(u64 val) +{ + /* Only preserve the minimal set of bits we support */ + val &= (SCTLR_ELx_M | SCTLR_ELx_A | SCTLR_ELx_C | SCTLR_ELx_SA | + SCTLR_ELx_I | SCTLR_ELx_IESB | SCTLR_ELx_WXN | SCTLR_ELx_EE); + val |= SCTLR_EL1_RES1; + + return val; +} + +static inline u64 translate_ttbr0_el2_to_ttbr0_el1(u64 ttbr0) +{ + /* Clear the ASID field */ + return ttbr0 & ~GENMASK_ULL(63, 48); +} + extern bool __check_nv_sr_forward(struct kvm_vcpu *vcpu); int kvm_init_nv_sysregs(struct kvm *kvm); From 60ce16cc122aad999129d23061fa35f63d5b1e9b Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 21 Jun 2019 13:54:37 +0100 Subject: [PATCH 06/10] KVM: arm64: nv: Add include containing the VNCR_EL2 offsets VNCR_EL2 points to a page containing a number of system registers accessed by a guest hypervisor when ARMv8.4-NV is enabled. Let's document the offsets in that page, as we are going to use this layout. Reviewed-by: Oliver Upton Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/vncr_mapping.h | 103 ++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100644 arch/arm64/include/asm/vncr_mapping.h diff --git a/arch/arm64/include/asm/vncr_mapping.h b/arch/arm64/include/asm/vncr_mapping.h new file mode 100644 index 000000000000..df2c47c55972 --- /dev/null +++ b/arch/arm64/include/asm/vncr_mapping.h @@ -0,0 +1,103 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * System register offsets in the VNCR page + * All offsets are *byte* displacements! + */ + +#ifndef __ARM64_VNCR_MAPPING_H__ +#define __ARM64_VNCR_MAPPING_H__ + +#define VNCR_VTTBR_EL2 0x020 +#define VNCR_VTCR_EL2 0x040 +#define VNCR_VMPIDR_EL2 0x050 +#define VNCR_CNTVOFF_EL2 0x060 +#define VNCR_HCR_EL2 0x078 +#define VNCR_HSTR_EL2 0x080 +#define VNCR_VPIDR_EL2 0x088 +#define VNCR_TPIDR_EL2 0x090 +#define VNCR_HCRX_EL2 0x0A0 +#define VNCR_VNCR_EL2 0x0B0 +#define VNCR_CPACR_EL1 0x100 +#define VNCR_CONTEXTIDR_EL1 0x108 +#define VNCR_SCTLR_EL1 0x110 +#define VNCR_ACTLR_EL1 0x118 +#define VNCR_TCR_EL1 0x120 +#define VNCR_AFSR0_EL1 0x128 +#define VNCR_AFSR1_EL1 0x130 +#define VNCR_ESR_EL1 0x138 +#define VNCR_MAIR_EL1 0x140 +#define VNCR_AMAIR_EL1 0x148 +#define VNCR_MDSCR_EL1 0x158 +#define VNCR_SPSR_EL1 0x160 +#define VNCR_CNTV_CVAL_EL0 0x168 +#define VNCR_CNTV_CTL_EL0 0x170 +#define VNCR_CNTP_CVAL_EL0 0x178 +#define VNCR_CNTP_CTL_EL0 0x180 +#define VNCR_SCXTNUM_EL1 0x188 +#define VNCR_TFSR_EL1 0x190 +#define VNCR_HFGRTR_EL2 0x1B8 +#define VNCR_HFGWTR_EL2 0x1C0 +#define VNCR_HFGITR_EL2 0x1C8 +#define VNCR_HDFGRTR_EL2 0x1D0 +#define VNCR_HDFGWTR_EL2 0x1D8 +#define VNCR_ZCR_EL1 0x1E0 +#define VNCR_HAFGRTR_EL2 0x1E8 +#define VNCR_TTBR0_EL1 0x200 +#define VNCR_TTBR1_EL1 0x210 +#define VNCR_FAR_EL1 0x220 +#define VNCR_ELR_EL1 0x230 +#define VNCR_SP_EL1 0x240 +#define VNCR_VBAR_EL1 0x250 +#define VNCR_TCR2_EL1 0x270 +#define VNCR_PIRE0_EL1 0x290 +#define VNCR_PIRE0_EL2 0x298 +#define VNCR_PIR_EL1 0x2A0 +#define VNCR_ICH_LR0_EL2 0x400 +#define VNCR_ICH_LR1_EL2 0x408 +#define VNCR_ICH_LR2_EL2 0x410 +#define VNCR_ICH_LR3_EL2 0x418 +#define VNCR_ICH_LR4_EL2 0x420 +#define VNCR_ICH_LR5_EL2 0x428 +#define VNCR_ICH_LR6_EL2 0x430 +#define VNCR_ICH_LR7_EL2 0x438 +#define VNCR_ICH_LR8_EL2 0x440 +#define VNCR_ICH_LR9_EL2 0x448 +#define VNCR_ICH_LR10_EL2 0x450 +#define VNCR_ICH_LR11_EL2 0x458 +#define VNCR_ICH_LR12_EL2 0x460 +#define VNCR_ICH_LR13_EL2 0x468 +#define VNCR_ICH_LR14_EL2 0x470 +#define VNCR_ICH_LR15_EL2 0x478 +#define VNCR_ICH_AP0R0_EL2 0x480 +#define VNCR_ICH_AP0R1_EL2 0x488 +#define VNCR_ICH_AP0R2_EL2 0x490 +#define VNCR_ICH_AP0R3_EL2 0x498 +#define VNCR_ICH_AP1R0_EL2 0x4A0 +#define VNCR_ICH_AP1R1_EL2 0x4A8 +#define VNCR_ICH_AP1R2_EL2 0x4B0 +#define VNCR_ICH_AP1R3_EL2 0x4B8 +#define VNCR_ICH_HCR_EL2 0x4C0 +#define VNCR_ICH_VMCR_EL2 0x4C8 +#define VNCR_VDISR_EL2 0x500 +#define VNCR_PMBLIMITR_EL1 0x800 +#define VNCR_PMBPTR_EL1 0x810 +#define VNCR_PMBSR_EL1 0x820 +#define VNCR_PMSCR_EL1 0x828 +#define VNCR_PMSEVFR_EL1 0x830 +#define VNCR_PMSICR_EL1 0x838 +#define VNCR_PMSIRR_EL1 0x840 +#define VNCR_PMSLATFR_EL1 0x848 +#define VNCR_TRFCR_EL1 0x880 +#define VNCR_MPAM1_EL1 0x900 +#define VNCR_MPAMHCR_EL2 0x930 +#define VNCR_MPAMVPMV_EL2 0x938 +#define VNCR_MPAMVPM0_EL2 0x940 +#define VNCR_MPAMVPM1_EL2 0x948 +#define VNCR_MPAMVPM2_EL2 0x950 +#define VNCR_MPAMVPM3_EL2 0x958 +#define VNCR_MPAMVPM4_EL2 0x960 +#define VNCR_MPAMVPM5_EL2 0x968 +#define VNCR_MPAMVPM6_EL2 0x970 +#define VNCR_MPAMVPM7_EL2 0x978 + +#endif /* __ARM64_VNCR_MAPPING_H__ */ From 2733dd10701abc6ab23d65a732f58fbeb80bd203 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 6 Nov 2023 16:42:13 +0000 Subject: [PATCH 07/10] KVM: arm64: Introduce a bad_trap() primitive for unexpected trap handling In order to ease the debugging of NV, it is helpful to have the kernel shout at you when an unexpected trap is handled. We already have this in a couple of cases. Make this a more generic infrastructure that we will make use of very shortly. Reviewed-by: Oliver Upton Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index cdfc79ccc7a1..3709c35666a2 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -45,24 +45,31 @@ static u64 sys_reg_to_index(const struct sys_reg_desc *reg); static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, u64 val); +static bool bad_trap(struct kvm_vcpu *vcpu, + struct sys_reg_params *params, + const struct sys_reg_desc *r, + const char *msg) +{ + WARN_ONCE(1, "Unexpected %s\n", msg); + print_sys_reg_instr(params); + kvm_inject_undefined(vcpu); + return false; +} + static bool read_from_write_only(struct kvm_vcpu *vcpu, struct sys_reg_params *params, const struct sys_reg_desc *r) { - WARN_ONCE(1, "Unexpected sys_reg read to write-only register\n"); - print_sys_reg_instr(params); - kvm_inject_undefined(vcpu); - return false; + return bad_trap(vcpu, params, r, + "sys_reg read to write-only register"); } static bool write_to_read_only(struct kvm_vcpu *vcpu, struct sys_reg_params *params, const struct sys_reg_desc *r) { - WARN_ONCE(1, "Unexpected sys_reg write to read-only register\n"); - print_sys_reg_instr(params); - kvm_inject_undefined(vcpu); - return false; + return bad_trap(vcpu, params, r, + "sys_reg write to read-only register"); } u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg) From 9b9cce60be85e6807bdb0eaa2f520e78dbab0659 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 7 Nov 2023 09:02:10 +0000 Subject: [PATCH 08/10] KVM: arm64: nv: Add EL2_REG_VNCR()/EL2_REG_REDIR() sysreg helpers Add two helpers to deal with EL2 registers are are either redirected to the VNCR page, or that are redirected to their EL1 counterpart. In either cases, no trap is expected. THe relevant register descriptors are repainted accordingly. Reviewed-by: Oliver Upton Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 65 ++++++++++++++++++++++++++++----------- 1 file changed, 47 insertions(+), 18 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 3709c35666a2..7fef170ec67b 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1890,6 +1890,32 @@ static unsigned int el2_visibility(const struct kvm_vcpu *vcpu, return REG_HIDDEN; } +static bool bad_vncr_trap(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + /* + * We really shouldn't be here, and this is likely the result + * of a misconfigured trap, as this register should target the + * VNCR page, and nothing else. + */ + return bad_trap(vcpu, p, r, + "trap of VNCR-backed register"); +} + +static bool bad_redir_trap(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + /* + * We really shouldn't be here, and this is likely the result + * of a misconfigured trap, as this register should target the + * corresponding EL1, and nothing else. + */ + return bad_trap(vcpu, p, r, + "trap of EL2 register redirected to EL1"); +} + #define EL2_REG(name, acc, rst, v) { \ SYS_DESC(SYS_##name), \ .access = acc, \ @@ -1899,6 +1925,9 @@ static unsigned int el2_visibility(const struct kvm_vcpu *vcpu, .val = v, \ } +#define EL2_REG_VNCR(name, rst, v) EL2_REG(name, bad_vncr_trap, rst, v) +#define EL2_REG_REDIR(name, rst, v) EL2_REG(name, bad_redir_trap, rst, v) + /* * EL{0,1}2 registers are the EL2 view on an EL0 or EL1 register when * HCR_EL2.E2H==1, and only in the sysreg table for convenience of @@ -2513,32 +2542,32 @@ static const struct sys_reg_desc sys_reg_descs[] = { { PMU_SYS_REG(PMCCFILTR_EL0), .access = access_pmu_evtyper, .reset = reset_val, .reg = PMCCFILTR_EL0, .val = 0 }, - EL2_REG(VPIDR_EL2, access_rw, reset_unknown, 0), - EL2_REG(VMPIDR_EL2, access_rw, reset_unknown, 0), + EL2_REG_VNCR(VPIDR_EL2, reset_unknown, 0), + EL2_REG_VNCR(VMPIDR_EL2, reset_unknown, 0), EL2_REG(SCTLR_EL2, access_rw, reset_val, SCTLR_EL2_RES1), EL2_REG(ACTLR_EL2, access_rw, reset_val, 0), - EL2_REG(HCR_EL2, access_rw, reset_val, 0), + EL2_REG_VNCR(HCR_EL2, reset_val, 0), EL2_REG(MDCR_EL2, access_rw, reset_val, 0), EL2_REG(CPTR_EL2, access_rw, reset_val, CPTR_NVHE_EL2_RES1), - EL2_REG(HSTR_EL2, access_rw, reset_val, 0), - EL2_REG(HFGRTR_EL2, access_rw, reset_val, 0), - EL2_REG(HFGWTR_EL2, access_rw, reset_val, 0), - EL2_REG(HFGITR_EL2, access_rw, reset_val, 0), - EL2_REG(HACR_EL2, access_rw, reset_val, 0), + EL2_REG_VNCR(HSTR_EL2, reset_val, 0), + EL2_REG_VNCR(HFGRTR_EL2, reset_val, 0), + EL2_REG_VNCR(HFGWTR_EL2, reset_val, 0), + EL2_REG_VNCR(HFGITR_EL2, reset_val, 0), + EL2_REG_VNCR(HACR_EL2, reset_val, 0), - EL2_REG(HCRX_EL2, access_rw, reset_val, 0), + EL2_REG_VNCR(HCRX_EL2, reset_val, 0), EL2_REG(TTBR0_EL2, access_rw, reset_val, 0), EL2_REG(TTBR1_EL2, access_rw, reset_val, 0), EL2_REG(TCR_EL2, access_rw, reset_val, TCR_EL2_RES1), - EL2_REG(VTTBR_EL2, access_rw, reset_val, 0), - EL2_REG(VTCR_EL2, access_rw, reset_val, 0), + EL2_REG_VNCR(VTTBR_EL2, reset_val, 0), + EL2_REG_VNCR(VTCR_EL2, reset_val, 0), { SYS_DESC(SYS_DACR32_EL2), trap_undef, reset_unknown, DACR32_EL2 }, - EL2_REG(HDFGRTR_EL2, access_rw, reset_val, 0), - EL2_REG(HDFGWTR_EL2, access_rw, reset_val, 0), - EL2_REG(SPSR_EL2, access_rw, reset_val, 0), - EL2_REG(ELR_EL2, access_rw, reset_val, 0), + EL2_REG_VNCR(HDFGRTR_EL2, reset_val, 0), + EL2_REG_VNCR(HDFGWTR_EL2, reset_val, 0), + EL2_REG_REDIR(SPSR_EL2, reset_val, 0), + EL2_REG_REDIR(ELR_EL2, reset_val, 0), { SYS_DESC(SYS_SP_EL1), access_sp_el1}, /* AArch32 SPSR_* are RES0 if trapped from a NV guest */ @@ -2554,10 +2583,10 @@ static const struct sys_reg_desc sys_reg_descs[] = { { SYS_DESC(SYS_IFSR32_EL2), trap_undef, reset_unknown, IFSR32_EL2 }, EL2_REG(AFSR0_EL2, access_rw, reset_val, 0), EL2_REG(AFSR1_EL2, access_rw, reset_val, 0), - EL2_REG(ESR_EL2, access_rw, reset_val, 0), + EL2_REG_REDIR(ESR_EL2, reset_val, 0), { SYS_DESC(SYS_FPEXC32_EL2), trap_undef, reset_val, FPEXC32_EL2, 0x700 }, - EL2_REG(FAR_EL2, access_rw, reset_val, 0), + EL2_REG_REDIR(FAR_EL2, reset_val, 0), EL2_REG(HPFAR_EL2, access_rw, reset_val, 0), EL2_REG(MAIR_EL2, access_rw, reset_val, 0), @@ -2570,7 +2599,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { EL2_REG(CONTEXTIDR_EL2, access_rw, reset_val, 0), EL2_REG(TPIDR_EL2, access_rw, reset_val, 0), - EL2_REG(CNTVOFF_EL2, access_rw, reset_val, 0), + EL2_REG_VNCR(CNTVOFF_EL2, reset_val, 0), EL2_REG(CNTHCTL_EL2, access_rw, reset_val, 0), EL12_REG(CNTKCTL, access_rw, reset_val, 0), From d8bd48e3f0ee9e1fdba2a2e453155a5354e48a8d Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 26 Jun 2019 19:59:56 +0100 Subject: [PATCH 09/10] KVM: arm64: nv: Map VNCR-capable registers to a separate page With ARMv8.4-NV, registers that can be directly accessed in memory by the guest have to live at architected offsets in a special page. Let's annotate the sysreg enum to reflect the offset at which they are in this page, whith a little twist: If running on HW that doesn't have the ARMv8.4-NV feature, or even a VM that doesn't use NV, we store all the system registers in the usual sys_regs array. The only difference with the pre-8.4 situation is that VNCR-capable registers are at a "similar" offset as in the VNCR page (we can compute the actual offset at compile time), and that the sys_regs array is both bigger and sparse. Reviewed-by: Oliver Upton Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_host.h | 127 +++++++++++++++++++----------- 1 file changed, 81 insertions(+), 46 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index fce2e5f583a7..9e8cd2bb95c3 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -27,6 +27,7 @@ #include #include #include +#include #define __KVM_HAVE_ARCH_INTC_INITIALIZED @@ -325,33 +326,33 @@ struct kvm_vcpu_fault_info { u64 disr_el1; /* Deferred [SError] Status Register */ }; +/* + * VNCR() just places the VNCR_capable registers in the enum after + * __VNCR_START__, and the value (after correction) to be an 8-byte offset + * from the VNCR base. As we don't require the enum to be otherwise ordered, + * we need the terrible hack below to ensure that we correctly size the + * sys_regs array, no matter what. + * + * The __MAX__ macro has been lifted from Sean Eron Anderson's wonderful + * treasure trove of bit hacks: + * https://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax + */ +#define __MAX__(x,y) ((x) ^ (((x) ^ (y)) & -((x) < (y)))) +#define VNCR(r) \ + __before_##r, \ + r = __VNCR_START__ + ((VNCR_ ## r) / 8), \ + __after_##r = __MAX__(__before_##r - 1, r) + enum vcpu_sysreg { __INVALID_SYSREG__, /* 0 is reserved as an invalid value */ MPIDR_EL1, /* MultiProcessor Affinity Register */ CLIDR_EL1, /* Cache Level ID Register */ CSSELR_EL1, /* Cache Size Selection Register */ - SCTLR_EL1, /* System Control Register */ - ACTLR_EL1, /* Auxiliary Control Register */ - CPACR_EL1, /* Coprocessor Access Control */ - ZCR_EL1, /* SVE Control */ - TTBR0_EL1, /* Translation Table Base Register 0 */ - TTBR1_EL1, /* Translation Table Base Register 1 */ - TCR_EL1, /* Translation Control Register */ - TCR2_EL1, /* Extended Translation Control Register */ - ESR_EL1, /* Exception Syndrome Register */ - AFSR0_EL1, /* Auxiliary Fault Status Register 0 */ - AFSR1_EL1, /* Auxiliary Fault Status Register 1 */ - FAR_EL1, /* Fault Address Register */ - MAIR_EL1, /* Memory Attribute Indirection Register */ - VBAR_EL1, /* Vector Base Address Register */ - CONTEXTIDR_EL1, /* Context ID Register */ TPIDR_EL0, /* Thread ID, User R/W */ TPIDRRO_EL0, /* Thread ID, User R/O */ TPIDR_EL1, /* Thread ID, Privileged */ - AMAIR_EL1, /* Aux Memory Attribute Indirection Register */ CNTKCTL_EL1, /* Timer Control Register (EL1) */ PAR_EL1, /* Physical Address Register */ - MDSCR_EL1, /* Monitor Debug System Control Register */ MDCCINT_EL1, /* Monitor Debug Comms Channel Interrupt Enable Reg */ OSLSR_EL1, /* OS Lock Status Register */ DISR_EL1, /* Deferred Interrupt Status Register */ @@ -382,26 +383,11 @@ enum vcpu_sysreg { APGAKEYLO_EL1, APGAKEYHI_EL1, - ELR_EL1, - SP_EL1, - SPSR_EL1, - - CNTVOFF_EL2, - CNTV_CVAL_EL0, - CNTV_CTL_EL0, - CNTP_CVAL_EL0, - CNTP_CTL_EL0, - /* Memory Tagging Extension registers */ RGSR_EL1, /* Random Allocation Tag Seed Register */ GCR_EL1, /* Tag Control Register */ - TFSR_EL1, /* Tag Fault Status Register (EL1) */ TFSRE0_EL1, /* Tag Fault Status Register (EL0) */ - /* Permission Indirection Extension registers */ - PIR_EL1, /* Permission Indirection Register 1 (EL1) */ - PIRE0_EL1, /* Permission Indirection Register 0 (EL1) */ - /* 32bit specific registers. */ DACR32_EL2, /* Domain Access Control Register */ IFSR32_EL2, /* Instruction Fault Status Register */ @@ -409,21 +395,14 @@ enum vcpu_sysreg { DBGVCR32_EL2, /* Debug Vector Catch Register */ /* EL2 registers */ - VPIDR_EL2, /* Virtualization Processor ID Register */ - VMPIDR_EL2, /* Virtualization Multiprocessor ID Register */ SCTLR_EL2, /* System Control Register (EL2) */ ACTLR_EL2, /* Auxiliary Control Register (EL2) */ - HCR_EL2, /* Hypervisor Configuration Register */ MDCR_EL2, /* Monitor Debug Configuration Register (EL2) */ CPTR_EL2, /* Architectural Feature Trap Register (EL2) */ - HSTR_EL2, /* Hypervisor System Trap Register */ HACR_EL2, /* Hypervisor Auxiliary Control Register */ - HCRX_EL2, /* Extended Hypervisor Configuration Register */ TTBR0_EL2, /* Translation Table Base Register 0 (EL2) */ TTBR1_EL2, /* Translation Table Base Register 1 (EL2) */ TCR_EL2, /* Translation Control Register (EL2) */ - VTTBR_EL2, /* Virtualization Translation Table Base Register */ - VTCR_EL2, /* Virtualization Translation Control Register */ SPSR_EL2, /* EL2 saved program status register */ ELR_EL2, /* EL2 exception link register */ AFSR0_EL2, /* Auxiliary Fault Status Register 0 (EL2) */ @@ -436,19 +415,61 @@ enum vcpu_sysreg { VBAR_EL2, /* Vector Base Address Register (EL2) */ RVBAR_EL2, /* Reset Vector Base Address Register */ CONTEXTIDR_EL2, /* Context ID Register (EL2) */ - TPIDR_EL2, /* EL2 Software Thread ID Register */ CNTHCTL_EL2, /* Counter-timer Hypervisor Control register */ SP_EL2, /* EL2 Stack Pointer */ - HFGRTR_EL2, - HFGWTR_EL2, - HFGITR_EL2, - HDFGRTR_EL2, - HDFGWTR_EL2, CNTHP_CTL_EL2, CNTHP_CVAL_EL2, CNTHV_CTL_EL2, CNTHV_CVAL_EL2, + __VNCR_START__, /* Any VNCR-capable reg goes after this point */ + + VNCR(SCTLR_EL1),/* System Control Register */ + VNCR(ACTLR_EL1),/* Auxiliary Control Register */ + VNCR(CPACR_EL1),/* Coprocessor Access Control */ + VNCR(ZCR_EL1), /* SVE Control */ + VNCR(TTBR0_EL1),/* Translation Table Base Register 0 */ + VNCR(TTBR1_EL1),/* Translation Table Base Register 1 */ + VNCR(TCR_EL1), /* Translation Control Register */ + VNCR(TCR2_EL1), /* Extended Translation Control Register */ + VNCR(ESR_EL1), /* Exception Syndrome Register */ + VNCR(AFSR0_EL1),/* Auxiliary Fault Status Register 0 */ + VNCR(AFSR1_EL1),/* Auxiliary Fault Status Register 1 */ + VNCR(FAR_EL1), /* Fault Address Register */ + VNCR(MAIR_EL1), /* Memory Attribute Indirection Register */ + VNCR(VBAR_EL1), /* Vector Base Address Register */ + VNCR(CONTEXTIDR_EL1), /* Context ID Register */ + VNCR(AMAIR_EL1),/* Aux Memory Attribute Indirection Register */ + VNCR(MDSCR_EL1),/* Monitor Debug System Control Register */ + VNCR(ELR_EL1), + VNCR(SP_EL1), + VNCR(SPSR_EL1), + VNCR(TFSR_EL1), /* Tag Fault Status Register (EL1) */ + VNCR(VPIDR_EL2),/* Virtualization Processor ID Register */ + VNCR(VMPIDR_EL2),/* Virtualization Multiprocessor ID Register */ + VNCR(HCR_EL2), /* Hypervisor Configuration Register */ + VNCR(HSTR_EL2), /* Hypervisor System Trap Register */ + VNCR(VTTBR_EL2),/* Virtualization Translation Table Base Register */ + VNCR(VTCR_EL2), /* Virtualization Translation Control Register */ + VNCR(TPIDR_EL2),/* EL2 Software Thread ID Register */ + VNCR(HCRX_EL2), /* Extended Hypervisor Configuration Register */ + + /* Permission Indirection Extension registers */ + VNCR(PIR_EL1), /* Permission Indirection Register 1 (EL1) */ + VNCR(PIRE0_EL1), /* Permission Indirection Register 0 (EL1) */ + + VNCR(HFGRTR_EL2), + VNCR(HFGWTR_EL2), + VNCR(HFGITR_EL2), + VNCR(HDFGRTR_EL2), + VNCR(HDFGWTR_EL2), + + VNCR(CNTVOFF_EL2), + VNCR(CNTV_CVAL_EL0), + VNCR(CNTV_CTL_EL0), + VNCR(CNTP_CVAL_EL0), + VNCR(CNTP_CTL_EL0), + NR_SYS_REGS /* Nothing after this line! */ }; @@ -465,6 +486,9 @@ struct kvm_cpu_context { u64 sys_regs[NR_SYS_REGS]; struct kvm_vcpu *__hyp_running_vcpu; + + /* This pointer has to be 4kB aligned. */ + u64 *vncr_array; }; struct kvm_host_data { @@ -827,8 +851,19 @@ struct kvm_vcpu_arch { * accessed by a running VCPU. For example, for userspace access or * for system registers that are never context switched, but only * emulated. + * + * Don't bother with VNCR-based accesses in the nVHE code, it has no + * business dealing with NV. */ -#define __ctxt_sys_reg(c,r) (&(c)->sys_regs[(r)]) +static inline u64 *__ctxt_sys_reg(const struct kvm_cpu_context *ctxt, int r) +{ +#if !defined (__KVM_NVHE_HYPERVISOR__) + if (unlikely(cpus_have_final_cap(ARM64_HAS_NESTED_VIRT) && + r >= __VNCR_START__ && ctxt->vncr_array)) + return &ctxt->vncr_array[r - __VNCR_START__]; +#endif + return (u64 *)&ctxt->sys_regs[r]; +} #define ctxt_sys_reg(c,r) (*__ctxt_sys_reg(c,r)) From fedc612314acfebf506e071bf3a941076aa56d10 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Sat, 17 Dec 2022 13:28:40 +0000 Subject: [PATCH 10/10] KVM: arm64: nv: Handle virtual EL2 registers in vcpu_read/write_sys_reg() KVM internally uses accessor functions when reading or writing the guest's system registers. This takes care of accessing either the stored copy or using the "live" EL1 system registers when the host uses VHE. With the introduction of virtual EL2 we add a bunch of EL2 system registers, which now must also be taken care of: - If the guest is running in vEL2, and we access an EL1 sysreg, we must revert to the stored version of that, and not use the CPU's copy. - If the guest is running in vEL1, and we access an EL2 sysreg, we must also use the stored version, since the CPU carries the EL1 copy. - Some EL2 system registers are supposed to affect the current execution of the system, so we need to put them into their respective EL1 counterparts. For this we need to define a mapping between the two. - Some EL2 system registers have a different format than their EL1 counterpart, so we need to translate them before writing them to the CPU. This is done using an (optional) translate function in the map. All of these cases are now wrapped into the existing accessor functions, so KVM users wouldn't need to care whether they access EL2 or EL1 registers and also which state the guest is in. Reviewed-by: Ganapatrao Kulkarni Reviewed-by: Alexandru Elisei Reviewed-by: Russell King (Oracle) Reviewed-by: Oliver Upton Co-developed-by: Andre Przywara Signed-off-by: Andre Przywara Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_host.h | 2 + arch/arm64/kvm/sys_regs.c | 129 ++++++++++++++++++++++++++++-- 2 files changed, 126 insertions(+), 5 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 9e8cd2bb95c3..f17fb7c42973 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -907,6 +907,7 @@ static inline bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val) case AMAIR_EL1: *val = read_sysreg_s(SYS_AMAIR_EL12); break; case CNTKCTL_EL1: *val = read_sysreg_s(SYS_CNTKCTL_EL12); break; case ELR_EL1: *val = read_sysreg_s(SYS_ELR_EL12); break; + case SPSR_EL1: *val = read_sysreg_s(SYS_SPSR_EL12); break; case PAR_EL1: *val = read_sysreg_par(); break; case DACR32_EL2: *val = read_sysreg_s(SYS_DACR32_EL2); break; case IFSR32_EL2: *val = read_sysreg_s(SYS_IFSR32_EL2); break; @@ -951,6 +952,7 @@ static inline bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg) case AMAIR_EL1: write_sysreg_s(val, SYS_AMAIR_EL12); break; case CNTKCTL_EL1: write_sysreg_s(val, SYS_CNTKCTL_EL12); break; case ELR_EL1: write_sysreg_s(val, SYS_ELR_EL12); break; + case SPSR_EL1: write_sysreg_s(val, SYS_SPSR_EL12); break; case PAR_EL1: write_sysreg_s(val, SYS_PAR_EL1); break; case DACR32_EL2: write_sysreg_s(val, SYS_DACR32_EL2); break; case IFSR32_EL2: write_sysreg_s(val, SYS_IFSR32_EL2); break; diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 7fef170ec67b..3198542dcded 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -72,24 +72,143 @@ static bool write_to_read_only(struct kvm_vcpu *vcpu, "sys_reg write to read-only register"); } +#define PURE_EL2_SYSREG(el2) \ + case el2: { \ + *el1r = el2; \ + return true; \ + } + +#define MAPPED_EL2_SYSREG(el2, el1, fn) \ + case el2: { \ + *xlate = fn; \ + *el1r = el1; \ + return true; \ + } + +static bool get_el2_to_el1_mapping(unsigned int reg, + unsigned int *el1r, u64 (**xlate)(u64)) +{ + switch (reg) { + PURE_EL2_SYSREG( VPIDR_EL2 ); + PURE_EL2_SYSREG( VMPIDR_EL2 ); + PURE_EL2_SYSREG( ACTLR_EL2 ); + PURE_EL2_SYSREG( HCR_EL2 ); + PURE_EL2_SYSREG( MDCR_EL2 ); + PURE_EL2_SYSREG( HSTR_EL2 ); + PURE_EL2_SYSREG( HACR_EL2 ); + PURE_EL2_SYSREG( VTTBR_EL2 ); + PURE_EL2_SYSREG( VTCR_EL2 ); + PURE_EL2_SYSREG( RVBAR_EL2 ); + PURE_EL2_SYSREG( TPIDR_EL2 ); + PURE_EL2_SYSREG( HPFAR_EL2 ); + PURE_EL2_SYSREG( CNTHCTL_EL2 ); + MAPPED_EL2_SYSREG(SCTLR_EL2, SCTLR_EL1, + translate_sctlr_el2_to_sctlr_el1 ); + MAPPED_EL2_SYSREG(CPTR_EL2, CPACR_EL1, + translate_cptr_el2_to_cpacr_el1 ); + MAPPED_EL2_SYSREG(TTBR0_EL2, TTBR0_EL1, + translate_ttbr0_el2_to_ttbr0_el1 ); + MAPPED_EL2_SYSREG(TTBR1_EL2, TTBR1_EL1, NULL ); + MAPPED_EL2_SYSREG(TCR_EL2, TCR_EL1, + translate_tcr_el2_to_tcr_el1 ); + MAPPED_EL2_SYSREG(VBAR_EL2, VBAR_EL1, NULL ); + MAPPED_EL2_SYSREG(AFSR0_EL2, AFSR0_EL1, NULL ); + MAPPED_EL2_SYSREG(AFSR1_EL2, AFSR1_EL1, NULL ); + MAPPED_EL2_SYSREG(ESR_EL2, ESR_EL1, NULL ); + MAPPED_EL2_SYSREG(FAR_EL2, FAR_EL1, NULL ); + MAPPED_EL2_SYSREG(MAIR_EL2, MAIR_EL1, NULL ); + MAPPED_EL2_SYSREG(AMAIR_EL2, AMAIR_EL1, NULL ); + MAPPED_EL2_SYSREG(ELR_EL2, ELR_EL1, NULL ); + MAPPED_EL2_SYSREG(SPSR_EL2, SPSR_EL1, NULL ); + default: + return false; + } +} + u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg) { u64 val = 0x8badf00d8badf00d; + u64 (*xlate)(u64) = NULL; + unsigned int el1r; - if (vcpu_get_flag(vcpu, SYSREGS_ON_CPU) && - __vcpu_read_sys_reg_from_cpu(reg, &val)) + if (!vcpu_get_flag(vcpu, SYSREGS_ON_CPU)) + goto memory_read; + + if (unlikely(get_el2_to_el1_mapping(reg, &el1r, &xlate))) { + if (!is_hyp_ctxt(vcpu)) + goto memory_read; + + /* + * If this register does not have an EL1 counterpart, + * then read the stored EL2 version. + */ + if (reg == el1r) + goto memory_read; + + /* + * If we have a non-VHE guest and that the sysreg + * requires translation to be used at EL1, use the + * in-memory copy instead. + */ + if (!vcpu_el2_e2h_is_set(vcpu) && xlate) + goto memory_read; + + /* Get the current version of the EL1 counterpart. */ + WARN_ON(!__vcpu_read_sys_reg_from_cpu(el1r, &val)); + return val; + } + + /* EL1 register can't be on the CPU if the guest is in vEL2. */ + if (unlikely(is_hyp_ctxt(vcpu))) + goto memory_read; + + if (__vcpu_read_sys_reg_from_cpu(reg, &val)) return val; +memory_read: return __vcpu_sys_reg(vcpu, reg); } void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) { - if (vcpu_get_flag(vcpu, SYSREGS_ON_CPU) && - __vcpu_write_sys_reg_to_cpu(val, reg)) + u64 (*xlate)(u64) = NULL; + unsigned int el1r; + + if (!vcpu_get_flag(vcpu, SYSREGS_ON_CPU)) + goto memory_write; + + if (unlikely(get_el2_to_el1_mapping(reg, &el1r, &xlate))) { + if (!is_hyp_ctxt(vcpu)) + goto memory_write; + + /* + * Always store a copy of the write to memory to avoid having + * to reverse-translate virtual EL2 system registers for a + * non-VHE guest hypervisor. + */ + __vcpu_sys_reg(vcpu, reg) = val; + + /* No EL1 counterpart? We're done here.? */ + if (reg == el1r) + return; + + if (!vcpu_el2_e2h_is_set(vcpu) && xlate) + val = xlate(val); + + /* Redirect this to the EL1 version of the register. */ + WARN_ON(!__vcpu_write_sys_reg_to_cpu(val, el1r)); + return; + } + + /* EL1 register can't be on the CPU if the guest is in vEL2. */ + if (unlikely(is_hyp_ctxt(vcpu))) + goto memory_write; + + if (__vcpu_write_sys_reg_to_cpu(val, reg)) return; - __vcpu_sys_reg(vcpu, reg) = val; +memory_write: + __vcpu_sys_reg(vcpu, reg) = val; } /* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */