FAILED: patch "[PATCH] KVM: arm64: Check for SYSREGS_ON_CPU before accessing the CPU" failed to apply to 6.15-stable tree
The patch below does not apply to the 6.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.15.y git checkout FETCH_HEAD git cherry-pick -x c6e35dff58d348c1a9489e9b3b62b3721e62631d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025081248-omission-talisman-0619@gregkh' --subject-prefix 'PATCH 6.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From c6e35dff58d348c1a9489e9b3b62b3721e62631d Mon Sep 17 00:00:00 2001 From: Marc Zyngier maz@kernel.org Date: Sun, 20 Jul 2025 11:22:29 +0100 Subject: [PATCH] KVM: arm64: Check for SYSREGS_ON_CPU before accessing the CPU state
Mark Brown reports that since we commit to making exceptions visible without the vcpu being loaded, the external abort selftest fails.
Upon investigation, it turns out that the code that makes registers affected by an exception visible to the guest is completely broken on VHE, as we don't check whether the system registers are loaded on the CPU at this point. We managed to get away with this so far, but that's obviously as bad as it gets,
Add the required checksm and document the absolute need to check for the SYSREGS_ON_CPU flag before calling into any of the __vcpu_write_sys_reg_to_cpu()__vcpu_read_sys_reg_from_cpu() helpers.
Reported-by: Mark Brown broonie@kernel.org Signed-off-by: Marc Zyngier maz@kernel.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/18535df8-e647-4643-af9a-bb780af03a70@sirena.org.uk Link: https://lore.kernel.org/r/20250720102229.179114-1-maz@kernel.org Signed-off-by: Oliver Upton oliver.upton@linux.dev
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index e54d29feb469..d373d555a69b 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1169,6 +1169,8 @@ static inline bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val) * System registers listed in the switch are not saved on every * exit from the guest but are only saved on vcpu_put. * + * SYSREGS_ON_CPU *MUST* be checked before using this helper. + * * Note that MPIDR_EL1 for the guest is set by KVM via VMPIDR_EL2 but * should never be listed below, because the guest cannot modify its * own MPIDR_EL1 and MPIDR_EL1 is accessed for VCPU A from VCPU B's @@ -1221,6 +1223,8 @@ static inline bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg) * System registers listed in the switch are not restored on every * entry to the guest but are only restored on vcpu_load. * + * SYSREGS_ON_CPU *MUST* be checked before using this helper. + * * Note that MPIDR_EL1 for the guest is set by KVM via VMPIDR_EL2 but * should never be listed below, because the MPIDR should only be set * once, before running the VCPU, and never changed later. diff --git a/arch/arm64/kvm/hyp/exception.c b/arch/arm64/kvm/hyp/exception.c index 7dafd10e52e8..95d186e0bf54 100644 --- a/arch/arm64/kvm/hyp/exception.c +++ b/arch/arm64/kvm/hyp/exception.c @@ -26,7 +26,8 @@ static inline u64 __vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)
if (unlikely(vcpu_has_nv(vcpu))) return vcpu_read_sys_reg(vcpu, reg); - else if (__vcpu_read_sys_reg_from_cpu(reg, &val)) + else if (vcpu_get_flag(vcpu, SYSREGS_ON_CPU) && + __vcpu_read_sys_reg_from_cpu(reg, &val)) return val;
return __vcpu_sys_reg(vcpu, reg); @@ -36,7 +37,8 @@ static inline void __vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) { if (unlikely(vcpu_has_nv(vcpu))) vcpu_write_sys_reg(vcpu, val, reg); - else if (!__vcpu_write_sys_reg_to_cpu(val, reg)) + else if (!vcpu_get_flag(vcpu, SYSREGS_ON_CPU) || + !__vcpu_write_sys_reg_to_cpu(val, reg)) __vcpu_assign_sys_reg(vcpu, reg, val); }
From: Marc Zyngier maz@kernel.org
[ Upstream commit f12b54d7c24388886277598236b3eeea5c68eec4 ]
The pmcr_n field obviously refers to PMCR_EL0.N, but is generally used as the number of counters seen by the guest. Rename it accordingly.
Suggested-by: Oliver upton oliver.upton@linux.dev Signed-off-by: Marc Zyngier maz@kernel.org Stable-dep-of: c6e35dff58d3 ("KVM: arm64: Check for SYSREGS_ON_CPU before accessing the CPU state") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/include/asm/kvm_host.h | 4 ++-- arch/arm64/kvm/pmu-emul.c | 6 +++--- arch/arm64/kvm/sys_regs.c | 4 ++-- 3 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 08ba91e6fb03..bea8ae1b1b02 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -359,8 +359,8 @@ struct kvm_arch {
cpumask_var_t supported_cpus;
- /* PMCR_EL0.N value for the guest */ - u8 pmcr_n; + /* Maximum number of counters for the guest */ + u8 nr_pmu_counters;
/* Iterator for idreg debugfs */ u8 idreg_debugfs_iter; diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index a1bc10d7116a..60b5a5e4a6c5 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -280,7 +280,7 @@ static u64 kvm_pmu_hyp_counter_mask(struct kvm_vcpu *vcpu) return 0;
hpmn = SYS_FIELD_GET(MDCR_EL2, HPMN, __vcpu_sys_reg(vcpu, MDCR_EL2)); - n = vcpu->kvm->arch.pmcr_n; + n = vcpu->kvm->arch.nr_pmu_counters;
/* * Programming HPMN to a value greater than PMCR_EL0.N is @@ -1032,7 +1032,7 @@ static void kvm_arm_set_pmu(struct kvm *kvm, struct arm_pmu *arm_pmu) lockdep_assert_held(&kvm->arch.config_lock);
kvm->arch.arm_pmu = arm_pmu; - kvm->arch.pmcr_n = kvm_arm_pmu_get_max_counters(kvm); + kvm->arch.nr_pmu_counters = kvm_arm_pmu_get_max_counters(kvm); }
/** @@ -1261,7 +1261,7 @@ u64 kvm_vcpu_read_pmcr(struct kvm_vcpu *vcpu) { u64 pmcr = __vcpu_sys_reg(vcpu, PMCR_EL0);
- return u64_replace_bits(pmcr, vcpu->kvm->arch.pmcr_n, ARMV8_PMU_PMCR_N); + return u64_replace_bits(pmcr, vcpu->kvm->arch.nr_pmu_counters, ARMV8_PMU_PMCR_N); }
void kvm_pmu_nested_transition(struct kvm_vcpu *vcpu) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 5dde9285afc8..554490360ff6 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -785,7 +785,7 @@ static unsigned int pmu_visibility(const struct kvm_vcpu *vcpu, static u64 reset_pmu_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { u64 mask = BIT(ARMV8_PMU_CYCLE_IDX); - u8 n = vcpu->kvm->arch.pmcr_n; + u8 n = vcpu->kvm->arch.nr_pmu_counters;
if (n) mask |= GENMASK(n - 1, 0); @@ -1217,7 +1217,7 @@ static int set_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, */ if (!kvm_vm_has_ran_once(kvm) && new_n <= kvm_arm_pmu_get_max_counters(kvm)) - kvm->arch.pmcr_n = new_n; + kvm->arch.nr_pmu_counters = new_n;
mutex_unlock(&kvm->arch.config_lock);
From: Marc Zyngier maz@kernel.org
[ Upstream commit c8823e51b534d490ec27d372596eb35d2bb7193c ]
The MDCR_EL2 documentation indicates that the HPMN field has the following behaviour:
"On a Warm reset, this field resets to the expression NUM_PMU_COUNTERS."
However, it appears we reset it to zero, which is not very useful.
Add a reset helper for MDCR_EL2, and handle the case where userspace changes the target PMU, which may force us to change HPMN again.
Reported-by: Joey Gouly joey.gouly@arm.com Reviewed-by: Oliver Upton oliver.upton@linux.dev Signed-off-by: Marc Zyngier maz@kernel.org Stable-dep-of: c6e35dff58d3 ("KVM: arm64: Check for SYSREGS_ON_CPU before accessing the CPU state") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/kvm/pmu-emul.c | 20 +++++++++++++++++++- arch/arm64/kvm/sys_regs.c | 8 +++++++- 2 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index 60b5a5e4a6c5..2df54508f5ae 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -1027,12 +1027,30 @@ u8 kvm_arm_pmu_get_max_counters(struct kvm *kvm) return bitmap_weight(arm_pmu->cntr_mask, ARMV8_PMU_MAX_GENERAL_COUNTERS); }
+static void kvm_arm_set_nr_counters(struct kvm *kvm, unsigned int nr) +{ + kvm->arch.nr_pmu_counters = nr; + + /* Reset MDCR_EL2.HPMN behind the vcpus' back... */ + if (test_bit(KVM_ARM_VCPU_HAS_EL2, kvm->arch.vcpu_features)) { + struct kvm_vcpu *vcpu; + unsigned long i; + + kvm_for_each_vcpu(i, vcpu, kvm) { + u64 val = __vcpu_sys_reg(vcpu, MDCR_EL2); + val &= ~MDCR_EL2_HPMN; + val |= FIELD_PREP(MDCR_EL2_HPMN, kvm->arch.nr_pmu_counters); + __vcpu_sys_reg(vcpu, MDCR_EL2) = val; + } + } +} + static void kvm_arm_set_pmu(struct kvm *kvm, struct arm_pmu *arm_pmu) { lockdep_assert_held(&kvm->arch.config_lock);
kvm->arch.arm_pmu = arm_pmu; - kvm->arch.nr_pmu_counters = kvm_arm_pmu_get_max_counters(kvm); + kvm_arm_set_nr_counters(kvm, kvm_arm_pmu_get_max_counters(kvm)); }
/** diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 554490360ff6..c1e900a66d35 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2704,6 +2704,12 @@ static int set_imp_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, .set_user = set_imp_id_reg, \ .reset = reset_imp_id_reg, \ .val = mask, \ + } + +static u64 reset_mdcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +{ + __vcpu_sys_reg(vcpu, r->reg) = vcpu->kvm->arch.nr_pmu_counters; + return vcpu->kvm->arch.nr_pmu_counters; }
/* @@ -3249,7 +3255,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { EL2_REG(SCTLR_EL2, access_rw, reset_val, SCTLR_EL2_RES1), EL2_REG(ACTLR_EL2, access_rw, reset_val, 0), EL2_REG_VNCR(HCR_EL2, reset_hcr, 0), - EL2_REG(MDCR_EL2, access_mdcr, reset_val, 0), + EL2_REG(MDCR_EL2, access_mdcr, reset_mdcr, 0), EL2_REG(CPTR_EL2, access_rw, reset_val, CPTR_NVHE_EL2_RES1), EL2_REG_VNCR(HSTR_EL2, reset_val, 0), EL2_REG_VNCR(HFGRTR_EL2, reset_val, 0),
From: Marc Zyngier maz@kernel.org
[ Upstream commit efff9dd2fee7a5969b5b2a04995e638c3ba15826 ]
We don't really pay attention to what gets written to MDCR_EL2.HPMN, and funky guests could play ugly games on us.
Restrict what gets written there, and limit the number of counters to what the PMU is allowed to have.
Reviewed-by: Oliver Upton oliver.upton@linux.dev Signed-off-by: Marc Zyngier maz@kernel.org Stable-dep-of: c6e35dff58d3 ("KVM: arm64: Check for SYSREGS_ON_CPU before accessing the CPU state") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/kvm/sys_regs.c | 29 +++++++++++++++++++++++------ 1 file changed, 23 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index c1e900a66d35..2ef68b66b950 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2576,16 +2576,33 @@ static bool access_mdcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - u64 old = __vcpu_sys_reg(vcpu, MDCR_EL2); + u64 hpmn, val, old = __vcpu_sys_reg(vcpu, MDCR_EL2);
- if (!access_rw(vcpu, p, r)) - return false; + if (!p->is_write) { + p->regval = old; + return true; + } + + val = p->regval; + hpmn = FIELD_GET(MDCR_EL2_HPMN, val); + + /* + * If HPMN is out of bounds, limit it to what we actually + * support. This matches the UNKNOWN definition of the field + * in that case, and keeps the emulation simple. Sort of. + */ + if (hpmn > vcpu->kvm->arch.nr_pmu_counters) { + hpmn = vcpu->kvm->arch.nr_pmu_counters; + u64_replace_bits(val, hpmn, MDCR_EL2_HPMN); + } + + __vcpu_sys_reg(vcpu, MDCR_EL2) = val;
/* - * Request a reload of the PMU to enable/disable the counters affected - * by HPME. + * Request a reload of the PMU to enable/disable the counters + * affected by HPME. */ - if ((old ^ __vcpu_sys_reg(vcpu, MDCR_EL2)) & MDCR_EL2_HPME) + if ((old ^ val) & MDCR_EL2_HPME) kvm_make_request(KVM_REQ_RELOAD_PMU, vcpu);
return true;
From: Marc Zyngier maz@kernel.org
[ Upstream commit 6678791ee3da0b78c28fe7d77814097f53cbb8df ]
Assigning a value to a system register doesn't do what it is supposed to be doing if that register is one that has RESx bits.
The main problem is that we use __vcpu_sys_reg(), which can be used both as a lvalue and rvalue. When used as a lvalue, the bit masking occurs *before* the new value is assigned, meaning that we (1) do pointless work on the old cvalue, and (2) potentially assign an invalid value as we fail to apply the masks to it.
Fix this by providing a new __vcpu_assign_sys_reg() that does what it says on the tin, and sanitises the *new* value instead of the old one. This comes with a significant amount of churn.
Reviewed-by: Miguel Luis miguel.luis@oracle.com Reviewed-by: Oliver Upton oliver.upton@linux.dev Link: https://lore.kernel.org/r/20250603070824.1192795-2-maz@kernel.org Signed-off-by: Marc Zyngier maz@kernel.org Stable-dep-of: c6e35dff58d3 ("KVM: arm64: Check for SYSREGS_ON_CPU before accessing the CPU state") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/include/asm/kvm_host.h | 11 ++++++ arch/arm64/kvm/arch_timer.c | 16 ++++---- arch/arm64/kvm/hyp/exception.c | 4 +- arch/arm64/kvm/hyp/include/hyp/switch.h | 4 +- arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 6 +-- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 4 +- arch/arm64/kvm/hyp/vhe/switch.c | 4 +- arch/arm64/kvm/hyp/vhe/sysreg-sr.c | 44 +++++++++++----------- arch/arm64/kvm/pmu-emul.c | 14 +++---- arch/arm64/kvm/sys_regs.c | 38 ++++++++++--------- arch/arm64/kvm/sys_regs.h | 4 +- arch/arm64/kvm/vgic/vgic-v3-nested.c | 10 ++--- 12 files changed, 86 insertions(+), 73 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index bea8ae1b1b02..12628bce1acd 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1050,6 +1050,17 @@ static inline u64 *___ctxt_sys_reg(const struct kvm_cpu_context *ctxt, int r) #define ctxt_sys_reg(c,r) (*__ctxt_sys_reg(c,r))
u64 kvm_vcpu_apply_reg_masks(const struct kvm_vcpu *, enum vcpu_sysreg, u64); + +#define __vcpu_assign_sys_reg(v, r, val) \ + do { \ + const struct kvm_cpu_context *ctxt = &(v)->arch.ctxt; \ + u64 __v = (val); \ + if (vcpu_has_nv((v)) && (r) >= __SANITISED_REG_START__) \ + __v = kvm_vcpu_apply_reg_masks((v), (r), __v); \ + \ + ctxt_sys_reg(ctxt, (r)) = __v; \ + } while (0) + #define __vcpu_sys_reg(v,r) \ (*({ \ const struct kvm_cpu_context *ctxt = &(v)->arch.ctxt; \ diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c index 5133dcbfe9f7..5a67a6d4d95b 100644 --- a/arch/arm64/kvm/arch_timer.c +++ b/arch/arm64/kvm/arch_timer.c @@ -108,16 +108,16 @@ static void timer_set_ctl(struct arch_timer_context *ctxt, u32 ctl)
switch(arch_timer_ctx_index(ctxt)) { case TIMER_VTIMER: - __vcpu_sys_reg(vcpu, CNTV_CTL_EL0) = ctl; + __vcpu_assign_sys_reg(vcpu, CNTV_CTL_EL0, ctl); break; case TIMER_PTIMER: - __vcpu_sys_reg(vcpu, CNTP_CTL_EL0) = ctl; + __vcpu_assign_sys_reg(vcpu, CNTP_CTL_EL0, ctl); break; case TIMER_HVTIMER: - __vcpu_sys_reg(vcpu, CNTHV_CTL_EL2) = ctl; + __vcpu_assign_sys_reg(vcpu, CNTHV_CTL_EL2, ctl); break; case TIMER_HPTIMER: - __vcpu_sys_reg(vcpu, CNTHP_CTL_EL2) = ctl; + __vcpu_assign_sys_reg(vcpu, CNTHP_CTL_EL2, ctl); break; default: WARN_ON(1); @@ -130,16 +130,16 @@ static void timer_set_cval(struct arch_timer_context *ctxt, u64 cval)
switch(arch_timer_ctx_index(ctxt)) { case TIMER_VTIMER: - __vcpu_sys_reg(vcpu, CNTV_CVAL_EL0) = cval; + __vcpu_assign_sys_reg(vcpu, CNTV_CVAL_EL0, cval); break; case TIMER_PTIMER: - __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0) = cval; + __vcpu_assign_sys_reg(vcpu, CNTP_CVAL_EL0, cval); break; case TIMER_HVTIMER: - __vcpu_sys_reg(vcpu, CNTHV_CVAL_EL2) = cval; + __vcpu_assign_sys_reg(vcpu, CNTHV_CVAL_EL2, cval); break; case TIMER_HPTIMER: - __vcpu_sys_reg(vcpu, CNTHP_CVAL_EL2) = cval; + __vcpu_assign_sys_reg(vcpu, CNTHP_CVAL_EL2, cval); break; default: WARN_ON(1); diff --git a/arch/arm64/kvm/hyp/exception.c b/arch/arm64/kvm/hyp/exception.c index 424a5107cddb..6a2a899a344e 100644 --- a/arch/arm64/kvm/hyp/exception.c +++ b/arch/arm64/kvm/hyp/exception.c @@ -37,7 +37,7 @@ static inline void __vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) if (unlikely(vcpu_has_nv(vcpu))) vcpu_write_sys_reg(vcpu, val, reg); else if (!__vcpu_write_sys_reg_to_cpu(val, reg)) - __vcpu_sys_reg(vcpu, reg) = val; + __vcpu_assign_sys_reg(vcpu, reg, val); }
static void __vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long target_mode, @@ -51,7 +51,7 @@ static void __vcpu_write_spsr(struct kvm_vcpu *vcpu, unsigned long target_mode, } else if (has_vhe()) { write_sysreg_el1(val, SYS_SPSR); } else { - __vcpu_sys_reg(vcpu, SPSR_EL1) = val; + __vcpu_assign_sys_reg(vcpu, SPSR_EL1, val); } }
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 96f625dc7256..3707cb6c7be8 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -45,7 +45,7 @@ static inline void __fpsimd_save_fpexc32(struct kvm_vcpu *vcpu) if (!vcpu_el1_is_32bit(vcpu)) return;
- __vcpu_sys_reg(vcpu, FPEXC32_EL2) = read_sysreg(fpexc32_el2); + __vcpu_assign_sys_reg(vcpu, FPEXC32_EL2, read_sysreg(fpexc32_el2)); }
static inline void __activate_traps_fpsimd32(struct kvm_vcpu *vcpu) @@ -412,7 +412,7 @@ static inline void fpsimd_lazy_switch_to_host(struct kvm_vcpu *vcpu) */ if (vcpu_has_sve(vcpu)) { zcr_el1 = read_sysreg_el1(SYS_ZCR); - __vcpu_sys_reg(vcpu, vcpu_sve_zcr_elx(vcpu)) = zcr_el1; + __vcpu_assign_sys_reg(vcpu, vcpu_sve_zcr_elx(vcpu), zcr_el1);
/* * The guest's state is always saved using the guest's max VL. diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h index b9cff893bbe0..4d0dbea4c56f 100644 --- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h +++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h @@ -307,11 +307,11 @@ static inline void __sysreg32_save_state(struct kvm_vcpu *vcpu) vcpu->arch.ctxt.spsr_irq = read_sysreg(spsr_irq); vcpu->arch.ctxt.spsr_fiq = read_sysreg(spsr_fiq);
- __vcpu_sys_reg(vcpu, DACR32_EL2) = read_sysreg(dacr32_el2); - __vcpu_sys_reg(vcpu, IFSR32_EL2) = read_sysreg(ifsr32_el2); + __vcpu_assign_sys_reg(vcpu, DACR32_EL2, read_sysreg(dacr32_el2)); + __vcpu_assign_sys_reg(vcpu, IFSR32_EL2, read_sysreg(ifsr32_el2));
if (has_vhe() || kvm_debug_regs_in_use(vcpu)) - __vcpu_sys_reg(vcpu, DBGVCR32_EL2) = read_sysreg(dbgvcr32_el2); + __vcpu_assign_sys_reg(vcpu, DBGVCR32_EL2, read_sysreg(dbgvcr32_el2)); }
static inline void __sysreg32_restore_state(struct kvm_vcpu *vcpu) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 2c37680d954c..fcefebf11744 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -26,7 +26,7 @@ void __kvm_hyp_host_forward_smc(struct kvm_cpu_context *host_ctxt);
static void __hyp_sve_save_guest(struct kvm_vcpu *vcpu) { - __vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR); + __vcpu_assign_sys_reg(vcpu, ZCR_EL1, read_sysreg_el1(SYS_ZCR)); /* * On saving/restoring guest sve state, always use the maximum VL for * the guest. The layout of the data when saving the sve state depends @@ -79,7 +79,7 @@ static void fpsimd_sve_sync(struct kvm_vcpu *vcpu)
has_fpmr = kvm_has_fpmr(kern_hyp_va(vcpu->kvm)); if (has_fpmr) - __vcpu_sys_reg(vcpu, FPMR) = read_sysreg_s(SYS_FPMR); + __vcpu_assign_sys_reg(vcpu, FPMR, read_sysreg_s(SYS_FPMR));
if (system_supports_sve()) __hyp_sve_restore_host(); diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index 731a0378ed13..6f6f3ba6c3ea 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -198,9 +198,9 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu) */ val = read_sysreg_el0(SYS_CNTP_CVAL); if (map.direct_ptimer == vcpu_ptimer(vcpu)) - __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0) = val; + __vcpu_assign_sys_reg(vcpu, CNTP_CVAL_EL0, val); if (map.direct_ptimer == vcpu_hptimer(vcpu)) - __vcpu_sys_reg(vcpu, CNTHP_CVAL_EL2) = val; + __vcpu_assign_sys_reg(vcpu, CNTHP_CVAL_EL2, val);
offset = read_sysreg_s(SYS_CNTPOFF_EL2);
diff --git a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c index 3814b0b2c937..34c7bf7fe9de 100644 --- a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c @@ -18,17 +18,17 @@ static void __sysreg_save_vel2_state(struct kvm_vcpu *vcpu) { /* These registers are common with EL1 */ - __vcpu_sys_reg(vcpu, PAR_EL1) = read_sysreg(par_el1); - __vcpu_sys_reg(vcpu, TPIDR_EL1) = read_sysreg(tpidr_el1); - - __vcpu_sys_reg(vcpu, ESR_EL2) = read_sysreg_el1(SYS_ESR); - __vcpu_sys_reg(vcpu, AFSR0_EL2) = read_sysreg_el1(SYS_AFSR0); - __vcpu_sys_reg(vcpu, AFSR1_EL2) = read_sysreg_el1(SYS_AFSR1); - __vcpu_sys_reg(vcpu, FAR_EL2) = read_sysreg_el1(SYS_FAR); - __vcpu_sys_reg(vcpu, MAIR_EL2) = read_sysreg_el1(SYS_MAIR); - __vcpu_sys_reg(vcpu, VBAR_EL2) = read_sysreg_el1(SYS_VBAR); - __vcpu_sys_reg(vcpu, CONTEXTIDR_EL2) = read_sysreg_el1(SYS_CONTEXTIDR); - __vcpu_sys_reg(vcpu, AMAIR_EL2) = read_sysreg_el1(SYS_AMAIR); + __vcpu_assign_sys_reg(vcpu, PAR_EL1, read_sysreg(par_el1)); + __vcpu_assign_sys_reg(vcpu, TPIDR_EL1, read_sysreg(tpidr_el1)); + + __vcpu_assign_sys_reg(vcpu, ESR_EL2, read_sysreg_el1(SYS_ESR)); + __vcpu_assign_sys_reg(vcpu, AFSR0_EL2, read_sysreg_el1(SYS_AFSR0)); + __vcpu_assign_sys_reg(vcpu, AFSR1_EL2, read_sysreg_el1(SYS_AFSR1)); + __vcpu_assign_sys_reg(vcpu, FAR_EL2, read_sysreg_el1(SYS_FAR)); + __vcpu_assign_sys_reg(vcpu, MAIR_EL2, read_sysreg_el1(SYS_MAIR)); + __vcpu_assign_sys_reg(vcpu, VBAR_EL2, read_sysreg_el1(SYS_VBAR)); + __vcpu_assign_sys_reg(vcpu, CONTEXTIDR_EL2, read_sysreg_el1(SYS_CONTEXTIDR)); + __vcpu_assign_sys_reg(vcpu, AMAIR_EL2, read_sysreg_el1(SYS_AMAIR));
/* * In VHE mode those registers are compatible between EL1 and EL2, @@ -46,21 +46,21 @@ static void __sysreg_save_vel2_state(struct kvm_vcpu *vcpu) * are always trapped, ensuring that the in-memory * copy is always up-to-date. A small blessing... */ - __vcpu_sys_reg(vcpu, SCTLR_EL2) = read_sysreg_el1(SYS_SCTLR); - __vcpu_sys_reg(vcpu, TTBR0_EL2) = read_sysreg_el1(SYS_TTBR0); - __vcpu_sys_reg(vcpu, TTBR1_EL2) = read_sysreg_el1(SYS_TTBR1); - __vcpu_sys_reg(vcpu, TCR_EL2) = read_sysreg_el1(SYS_TCR); + __vcpu_assign_sys_reg(vcpu, SCTLR_EL2, read_sysreg_el1(SYS_SCTLR)); + __vcpu_assign_sys_reg(vcpu, TTBR0_EL2, read_sysreg_el1(SYS_TTBR0)); + __vcpu_assign_sys_reg(vcpu, TTBR1_EL2, read_sysreg_el1(SYS_TTBR1)); + __vcpu_assign_sys_reg(vcpu, TCR_EL2, read_sysreg_el1(SYS_TCR));
if (ctxt_has_tcrx(&vcpu->arch.ctxt)) { - __vcpu_sys_reg(vcpu, TCR2_EL2) = read_sysreg_el1(SYS_TCR2); + __vcpu_assign_sys_reg(vcpu, TCR2_EL2, read_sysreg_el1(SYS_TCR2));
if (ctxt_has_s1pie(&vcpu->arch.ctxt)) { - __vcpu_sys_reg(vcpu, PIRE0_EL2) = read_sysreg_el1(SYS_PIRE0); - __vcpu_sys_reg(vcpu, PIR_EL2) = read_sysreg_el1(SYS_PIR); + __vcpu_assign_sys_reg(vcpu, PIRE0_EL2, read_sysreg_el1(SYS_PIRE0)); + __vcpu_assign_sys_reg(vcpu, PIR_EL2, read_sysreg_el1(SYS_PIR)); }
if (ctxt_has_s1poe(&vcpu->arch.ctxt)) - __vcpu_sys_reg(vcpu, POR_EL2) = read_sysreg_el1(SYS_POR); + __vcpu_assign_sys_reg(vcpu, POR_EL2, read_sysreg_el1(SYS_POR)); }
/* @@ -74,9 +74,9 @@ static void __sysreg_save_vel2_state(struct kvm_vcpu *vcpu) __vcpu_sys_reg(vcpu, CNTHCTL_EL2) |= val; }
- __vcpu_sys_reg(vcpu, SP_EL2) = read_sysreg(sp_el1); - __vcpu_sys_reg(vcpu, ELR_EL2) = read_sysreg_el1(SYS_ELR); - __vcpu_sys_reg(vcpu, SPSR_EL2) = read_sysreg_el1(SYS_SPSR); + __vcpu_assign_sys_reg(vcpu, SP_EL2, read_sysreg(sp_el1)); + __vcpu_assign_sys_reg(vcpu, ELR_EL2, read_sysreg_el1(SYS_ELR)); + __vcpu_assign_sys_reg(vcpu, SPSR_EL2, read_sysreg_el1(SYS_SPSR)); }
static void __sysreg_restore_vel2_state(struct kvm_vcpu *vcpu) diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index 2df54508f5ae..1fd4369a2b43 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -178,7 +178,7 @@ static void kvm_pmu_set_pmc_value(struct kvm_pmc *pmc, u64 val, bool force) val |= lower_32_bits(val); }
- __vcpu_sys_reg(vcpu, reg) = val; + __vcpu_assign_sys_reg(vcpu, reg, val);
/* Recreate the perf event to reflect the updated sample_period */ kvm_pmu_create_perf_event(pmc); @@ -204,7 +204,7 @@ void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val) void kvm_pmu_set_counter_value_user(struct kvm_vcpu *vcpu, u64 select_idx, u64 val) { kvm_pmu_release_perf_event(kvm_vcpu_idx_to_pmc(vcpu, select_idx)); - __vcpu_sys_reg(vcpu, counter_index_to_reg(select_idx)) = val; + __vcpu_assign_sys_reg(vcpu, counter_index_to_reg(select_idx), val); kvm_make_request(KVM_REQ_RELOAD_PMU, vcpu); }
@@ -239,7 +239,7 @@ static void kvm_pmu_stop_counter(struct kvm_pmc *pmc)
reg = counter_index_to_reg(pmc->idx);
- __vcpu_sys_reg(vcpu, reg) = val; + __vcpu_assign_sys_reg(vcpu, reg, val);
kvm_pmu_release_perf_event(pmc); } @@ -503,7 +503,7 @@ static void kvm_pmu_counter_increment(struct kvm_vcpu *vcpu, reg = __vcpu_sys_reg(vcpu, counter_index_to_reg(i)) + 1; if (!kvm_pmc_is_64bit(pmc)) reg = lower_32_bits(reg); - __vcpu_sys_reg(vcpu, counter_index_to_reg(i)) = reg; + __vcpu_assign_sys_reg(vcpu, counter_index_to_reg(i), reg);
/* No overflow? move on */ if (kvm_pmc_has_64bit_overflow(pmc) ? reg : lower_32_bits(reg)) @@ -602,7 +602,7 @@ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) kvm_make_request(KVM_REQ_RELOAD_PMU, vcpu);
/* The reset bits don't indicate any state, and shouldn't be saved. */ - __vcpu_sys_reg(vcpu, PMCR_EL0) = val & ~(ARMV8_PMU_PMCR_C | ARMV8_PMU_PMCR_P); + __vcpu_assign_sys_reg(vcpu, PMCR_EL0, (val & ~(ARMV8_PMU_PMCR_C | ARMV8_PMU_PMCR_P)));
if (val & ARMV8_PMU_PMCR_C) kvm_pmu_set_counter_value(vcpu, ARMV8_PMU_CYCLE_IDX, 0); @@ -781,7 +781,7 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, u64 reg;
reg = counter_index_to_evtreg(pmc->idx); - __vcpu_sys_reg(vcpu, reg) = data & kvm_pmu_evtyper_mask(vcpu->kvm); + __vcpu_assign_sys_reg(vcpu, reg, (data & kvm_pmu_evtyper_mask(vcpu->kvm)));
kvm_pmu_create_perf_event(pmc); } @@ -1040,7 +1040,7 @@ static void kvm_arm_set_nr_counters(struct kvm *kvm, unsigned int nr) u64 val = __vcpu_sys_reg(vcpu, MDCR_EL2); val &= ~MDCR_EL2_HPMN; val |= FIELD_PREP(MDCR_EL2_HPMN, kvm->arch.nr_pmu_counters); - __vcpu_sys_reg(vcpu, MDCR_EL2) = val; + __vcpu_assign_sys_reg(vcpu, MDCR_EL2, val); } } } diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 2ef68b66b950..2456d3b85666 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -228,7 +228,7 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) * to reverse-translate virtual EL2 system registers for a * non-VHE guest hypervisor. */ - __vcpu_sys_reg(vcpu, reg) = val; + __vcpu_assign_sys_reg(vcpu, reg, val);
switch (reg) { case CNTHCTL_EL2: @@ -263,7 +263,7 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) return;
memory_write: - __vcpu_sys_reg(vcpu, reg) = val; + __vcpu_assign_sys_reg(vcpu, reg, val); }
/* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */ @@ -605,7 +605,7 @@ static int set_oslsr_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, if ((val ^ rd->val) & ~OSLSR_EL1_OSLK) return -EINVAL;
- __vcpu_sys_reg(vcpu, rd->reg) = val; + __vcpu_assign_sys_reg(vcpu, rd->reg, val); return 0; }
@@ -835,7 +835,7 @@ static u64 reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) * The value of PMCR.N field is included when the * vCPU register is read via kvm_vcpu_read_pmcr(). */ - __vcpu_sys_reg(vcpu, r->reg) = pmcr; + __vcpu_assign_sys_reg(vcpu, r->reg, pmcr);
return __vcpu_sys_reg(vcpu, r->reg); } @@ -907,7 +907,7 @@ static bool access_pmselr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, return false;
if (p->is_write) - __vcpu_sys_reg(vcpu, PMSELR_EL0) = p->regval; + __vcpu_assign_sys_reg(vcpu, PMSELR_EL0, p->regval); else /* return PMSELR.SEL field */ p->regval = __vcpu_sys_reg(vcpu, PMSELR_EL0) @@ -1076,7 +1076,7 @@ static int set_pmreg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, u64 va { u64 mask = kvm_pmu_accessible_counter_mask(vcpu);
- __vcpu_sys_reg(vcpu, r->reg) = val & mask; + __vcpu_assign_sys_reg(vcpu, r->reg, val & mask); kvm_make_request(KVM_REQ_RELOAD_PMU, vcpu);
return 0; @@ -1185,8 +1185,8 @@ static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, if (!vcpu_mode_priv(vcpu)) return undef_access(vcpu, p, r);
- __vcpu_sys_reg(vcpu, PMUSERENR_EL0) = - p->regval & ARMV8_PMU_USERENR_MASK; + __vcpu_assign_sys_reg(vcpu, PMUSERENR_EL0, + (p->regval & ARMV8_PMU_USERENR_MASK)); } else { p->regval = __vcpu_sys_reg(vcpu, PMUSERENR_EL0) & ARMV8_PMU_USERENR_MASK; @@ -1236,7 +1236,7 @@ static int set_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, if (!kvm_supports_32bit_el0()) val |= ARMV8_PMU_PMCR_LC;
- __vcpu_sys_reg(vcpu, r->reg) = val; + __vcpu_assign_sys_reg(vcpu, r->reg, val); kvm_make_request(KVM_REQ_RELOAD_PMU, vcpu);
return 0; @@ -2188,7 +2188,7 @@ static u64 reset_clidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) if (kvm_has_mte(vcpu->kvm)) clidr |= 2ULL << CLIDR_TTYPE_SHIFT(loc);
- __vcpu_sys_reg(vcpu, r->reg) = clidr; + __vcpu_assign_sys_reg(vcpu, r->reg, clidr);
return __vcpu_sys_reg(vcpu, r->reg); } @@ -2202,7 +2202,7 @@ static int set_clidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, if ((val & CLIDR_EL1_RES0) || (!(ctr_el0 & CTR_EL0_IDC) && idc)) return -EINVAL;
- __vcpu_sys_reg(vcpu, rd->reg) = val; + __vcpu_assign_sys_reg(vcpu, rd->reg, val);
return 0; } @@ -2385,7 +2385,7 @@ static bool access_sp_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { if (p->is_write) - __vcpu_sys_reg(vcpu, SP_EL1) = p->regval; + __vcpu_assign_sys_reg(vcpu, SP_EL1, p->regval); else p->regval = __vcpu_sys_reg(vcpu, SP_EL1);
@@ -2409,7 +2409,7 @@ static bool access_spsr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { if (p->is_write) - __vcpu_sys_reg(vcpu, SPSR_EL1) = p->regval; + __vcpu_assign_sys_reg(vcpu, SPSR_EL1, p->regval); else p->regval = __vcpu_sys_reg(vcpu, SPSR_EL1);
@@ -2421,7 +2421,7 @@ static bool access_cntkctl_el12(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { if (p->is_write) - __vcpu_sys_reg(vcpu, CNTKCTL_EL1) = p->regval; + __vcpu_assign_sys_reg(vcpu, CNTKCTL_EL1, p->regval); else p->regval = __vcpu_sys_reg(vcpu, CNTKCTL_EL1);
@@ -2435,7 +2435,9 @@ static u64 reset_hcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) if (!cpus_have_final_cap(ARM64_HAS_HCR_NV1)) val |= HCR_E2H;
- return __vcpu_sys_reg(vcpu, r->reg) = val; + __vcpu_assign_sys_reg(vcpu, r->reg, val); + + return __vcpu_sys_reg(vcpu, r->reg); }
static unsigned int __el2_visibility(const struct kvm_vcpu *vcpu, @@ -2596,7 +2598,7 @@ static bool access_mdcr(struct kvm_vcpu *vcpu, u64_replace_bits(val, hpmn, MDCR_EL2_HPMN); }
- __vcpu_sys_reg(vcpu, MDCR_EL2) = val; + __vcpu_assign_sys_reg(vcpu, MDCR_EL2, val);
/* * Request a reload of the PMU to enable/disable the counters @@ -2725,7 +2727,7 @@ static int set_imp_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r,
static u64 reset_mdcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { - __vcpu_sys_reg(vcpu, r->reg) = vcpu->kvm->arch.nr_pmu_counters; + __vcpu_assign_sys_reg(vcpu, r->reg, vcpu->kvm->arch.nr_pmu_counters); return vcpu->kvm->arch.nr_pmu_counters; }
@@ -4966,7 +4968,7 @@ int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg, if (r->set_user) { ret = (r->set_user)(vcpu, r, val); } else { - __vcpu_sys_reg(vcpu, r->reg) = val; + __vcpu_assign_sys_reg(vcpu, r->reg, val); ret = 0; }
diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h index cc6338d38766..ef97d9fc67cc 100644 --- a/arch/arm64/kvm/sys_regs.h +++ b/arch/arm64/kvm/sys_regs.h @@ -137,7 +137,7 @@ static inline u64 reset_unknown(struct kvm_vcpu *vcpu, { BUG_ON(!r->reg); BUG_ON(r->reg >= NR_SYS_REGS); - __vcpu_sys_reg(vcpu, r->reg) = 0x1de7ec7edbadc0deULL; + __vcpu_assign_sys_reg(vcpu, r->reg, 0x1de7ec7edbadc0deULL); return __vcpu_sys_reg(vcpu, r->reg); }
@@ -145,7 +145,7 @@ static inline u64 reset_val(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { BUG_ON(!r->reg); BUG_ON(r->reg >= NR_SYS_REGS); - __vcpu_sys_reg(vcpu, r->reg) = r->val; + __vcpu_assign_sys_reg(vcpu, r->reg, r->val); return __vcpu_sys_reg(vcpu, r->reg); }
diff --git a/arch/arm64/kvm/vgic/vgic-v3-nested.c b/arch/arm64/kvm/vgic/vgic-v3-nested.c index bfa5bde1f106..3c2bcd66c110 100644 --- a/arch/arm64/kvm/vgic/vgic-v3-nested.c +++ b/arch/arm64/kvm/vgic/vgic-v3-nested.c @@ -359,12 +359,12 @@ void vgic_v3_put_nested(struct kvm_vcpu *vcpu) val = __vcpu_sys_reg(vcpu, ICH_HCR_EL2); val &= ~ICH_HCR_EL2_EOIcount_MASK; val |= (s_cpu_if->vgic_hcr & ICH_HCR_EL2_EOIcount_MASK); - __vcpu_sys_reg(vcpu, ICH_HCR_EL2) = val; - __vcpu_sys_reg(vcpu, ICH_VMCR_EL2) = s_cpu_if->vgic_vmcr; + __vcpu_assign_sys_reg(vcpu, ICH_HCR_EL2, val); + __vcpu_assign_sys_reg(vcpu, ICH_VMCR_EL2, s_cpu_if->vgic_vmcr);
for (i = 0; i < 4; i++) { - __vcpu_sys_reg(vcpu, ICH_AP0RN(i)) = s_cpu_if->vgic_ap0r[i]; - __vcpu_sys_reg(vcpu, ICH_AP1RN(i)) = s_cpu_if->vgic_ap1r[i]; + __vcpu_assign_sys_reg(vcpu, ICH_AP0RN(i), s_cpu_if->vgic_ap0r[i]); + __vcpu_assign_sys_reg(vcpu, ICH_AP1RN(i), s_cpu_if->vgic_ap1r[i]); }
for_each_set_bit(i, &shadow_if->lr_map, kvm_vgic_global_state.nr_lr) { @@ -373,7 +373,7 @@ void vgic_v3_put_nested(struct kvm_vcpu *vcpu) val &= ~ICH_LR_STATE; val |= s_cpu_if->vgic_lr[i] & ICH_LR_STATE;
- __vcpu_sys_reg(vcpu, ICH_LRN(i)) = val; + __vcpu_assign_sys_reg(vcpu, ICH_LRN(i), val); s_cpu_if->vgic_lr[i] = 0; }
From: Marc Zyngier maz@kernel.org
[ Upstream commit c6e35dff58d348c1a9489e9b3b62b3721e62631d ]
Mark Brown reports that since we commit to making exceptions visible without the vcpu being loaded, the external abort selftest fails.
Upon investigation, it turns out that the code that makes registers affected by an exception visible to the guest is completely broken on VHE, as we don't check whether the system registers are loaded on the CPU at this point. We managed to get away with this so far, but that's obviously as bad as it gets,
Add the required checksm and document the absolute need to check for the SYSREGS_ON_CPU flag before calling into any of the __vcpu_write_sys_reg_to_cpu()__vcpu_read_sys_reg_from_cpu() helpers.
Reported-by: Mark Brown broonie@kernel.org Signed-off-by: Marc Zyngier maz@kernel.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/18535df8-e647-4643-af9a-bb780af03a70@sirena.org.uk Link: https://lore.kernel.org/r/20250720102229.179114-1-maz@kernel.org Signed-off-by: Oliver Upton oliver.upton@linux.dev Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/include/asm/kvm_host.h | 4 ++++ arch/arm64/kvm/hyp/exception.c | 6 ++++-- 2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 12628bce1acd..cc4c7c15015d 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1081,6 +1081,8 @@ static inline bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val) * System registers listed in the switch are not saved on every * exit from the guest but are only saved on vcpu_put. * + * SYSREGS_ON_CPU *MUST* be checked before using this helper. + * * Note that MPIDR_EL1 for the guest is set by KVM via VMPIDR_EL2 but * should never be listed below, because the guest cannot modify its * own MPIDR_EL1 and MPIDR_EL1 is accessed for VCPU A from VCPU B's @@ -1132,6 +1134,8 @@ static inline bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg) * System registers listed in the switch are not restored on every * entry to the guest but are only restored on vcpu_load. * + * SYSREGS_ON_CPU *MUST* be checked before using this helper. + * * Note that MPIDR_EL1 for the guest is set by KVM via VMPIDR_EL2 but * should never be listed below, because the MPIDR should only be set * once, before running the VCPU, and never changed later. diff --git a/arch/arm64/kvm/hyp/exception.c b/arch/arm64/kvm/hyp/exception.c index 6a2a899a344e..9f5d837cc03f 100644 --- a/arch/arm64/kvm/hyp/exception.c +++ b/arch/arm64/kvm/hyp/exception.c @@ -26,7 +26,8 @@ static inline u64 __vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)
if (unlikely(vcpu_has_nv(vcpu))) return vcpu_read_sys_reg(vcpu, reg); - else if (__vcpu_read_sys_reg_from_cpu(reg, &val)) + else if (vcpu_get_flag(vcpu, SYSREGS_ON_CPU) && + __vcpu_read_sys_reg_from_cpu(reg, &val)) return val;
return __vcpu_sys_reg(vcpu, reg); @@ -36,7 +37,8 @@ static inline void __vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) { if (unlikely(vcpu_has_nv(vcpu))) vcpu_write_sys_reg(vcpu, val, reg); - else if (!__vcpu_write_sys_reg_to_cpu(val, reg)) + else if (!vcpu_get_flag(vcpu, SYSREGS_ON_CPU) || + !__vcpu_write_sys_reg_to_cpu(val, reg)) __vcpu_assign_sys_reg(vcpu, reg, val); }
Hi Sasha,
Please drop this series, it affects code that is effectively dead prior to 6.16.
Thanks, Oliver
On Wed, Aug 13, 2025 at 05:18:16PM -0400, Sasha Levin wrote:
From: Marc Zyngier maz@kernel.org
[ Upstream commit f12b54d7c24388886277598236b3eeea5c68eec4 ]
The pmcr_n field obviously refers to PMCR_EL0.N, but is generally used as the number of counters seen by the guest. Rename it accordingly.
Suggested-by: Oliver upton oliver.upton@linux.dev Signed-off-by: Marc Zyngier maz@kernel.org Stable-dep-of: c6e35dff58d3 ("KVM: arm64: Check for SYSREGS_ON_CPU before accessing the CPU state") Signed-off-by: Sasha Levin sashal@kernel.org
arch/arm64/include/asm/kvm_host.h | 4 ++-- arch/arm64/kvm/pmu-emul.c | 6 +++--- arch/arm64/kvm/sys_regs.c | 4 ++-- 3 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 08ba91e6fb03..bea8ae1b1b02 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -359,8 +359,8 @@ struct kvm_arch { cpumask_var_t supported_cpus;
- /* PMCR_EL0.N value for the guest */
- u8 pmcr_n;
- /* Maximum number of counters for the guest */
- u8 nr_pmu_counters;
/* Iterator for idreg debugfs */ u8 idreg_debugfs_iter; diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index a1bc10d7116a..60b5a5e4a6c5 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -280,7 +280,7 @@ static u64 kvm_pmu_hyp_counter_mask(struct kvm_vcpu *vcpu) return 0; hpmn = SYS_FIELD_GET(MDCR_EL2, HPMN, __vcpu_sys_reg(vcpu, MDCR_EL2));
- n = vcpu->kvm->arch.pmcr_n;
- n = vcpu->kvm->arch.nr_pmu_counters;
/* * Programming HPMN to a value greater than PMCR_EL0.N is @@ -1032,7 +1032,7 @@ static void kvm_arm_set_pmu(struct kvm *kvm, struct arm_pmu *arm_pmu) lockdep_assert_held(&kvm->arch.config_lock); kvm->arch.arm_pmu = arm_pmu;
- kvm->arch.pmcr_n = kvm_arm_pmu_get_max_counters(kvm);
- kvm->arch.nr_pmu_counters = kvm_arm_pmu_get_max_counters(kvm);
} /** @@ -1261,7 +1261,7 @@ u64 kvm_vcpu_read_pmcr(struct kvm_vcpu *vcpu) { u64 pmcr = __vcpu_sys_reg(vcpu, PMCR_EL0);
- return u64_replace_bits(pmcr, vcpu->kvm->arch.pmcr_n, ARMV8_PMU_PMCR_N);
- return u64_replace_bits(pmcr, vcpu->kvm->arch.nr_pmu_counters, ARMV8_PMU_PMCR_N);
} void kvm_pmu_nested_transition(struct kvm_vcpu *vcpu) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 5dde9285afc8..554490360ff6 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -785,7 +785,7 @@ static unsigned int pmu_visibility(const struct kvm_vcpu *vcpu, static u64 reset_pmu_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { u64 mask = BIT(ARMV8_PMU_CYCLE_IDX);
- u8 n = vcpu->kvm->arch.pmcr_n;
- u8 n = vcpu->kvm->arch.nr_pmu_counters;
if (n) mask |= GENMASK(n - 1, 0); @@ -1217,7 +1217,7 @@ static int set_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r, */ if (!kvm_vm_has_ran_once(kvm) && new_n <= kvm_arm_pmu_get_max_counters(kvm))
kvm->arch.pmcr_n = new_n;
kvm->arch.nr_pmu_counters = new_n;mutex_unlock(&kvm->arch.config_lock); -- 2.39.5
linux-stable-mirror@lists.linaro.org
-
gregkh＠linuxfoundation.org -
Oliver Upton -
Sasha Levin