diff options
author | Jing Zhang <jingzhangos@google.com> | 2023-06-09 22:00:48 +0300 |
---|---|---|
committer | Oliver Upton <oliver.upton@linux.dev> | 2023-06-13 02:08:33 +0300 |
commit | d86cde6e335fa442c6b0866562140a2bef25402a (patch) | |
tree | e73dbf2a6cc9bafa443b8107afcff935b6360834 /arch/arm64/kvm | |
parent | f90f9360c3d7fbb731732fbb9a1228f55d178e10 (diff) | |
download | linux-d86cde6e335fa442c6b0866562140a2bef25402a.tar.xz |
KVM: arm64: Reuse fields of sys_reg_desc for idreg
sys_reg_desc::{reset, val} are presently unused for ID register
descriptors. Repurpose these fields to support user-configurable ID
registers.
Use the ::reset() function pointer to return the sanitised value of a
given ID register, optionally with KVM-specific feature sanitisation.
Additionally, keep a mask of writable register fields in ::val.
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Link: https://lore.kernel.org/r/20230609190054.1542113-6-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64/kvm')
-rw-r--r-- | arch/arm64/kvm/sys_regs.c | 94 | ||||
-rw-r--r-- | arch/arm64/kvm/sys_regs.h | 15 |
2 files changed, 84 insertions, 25 deletions
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index e1ea7e0da5cd..9d37f16cfb7b 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -540,10 +540,11 @@ static int get_bvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, return 0; } -static void reset_bvr(struct kvm_vcpu *vcpu, +static u64 reset_bvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd) { vcpu->arch.vcpu_debug_state.dbg_bvr[rd->CRm] = rd->val; + return rd->val; } static bool trap_bcr(struct kvm_vcpu *vcpu, @@ -576,10 +577,11 @@ static int get_bcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, return 0; } -static void reset_bcr(struct kvm_vcpu *vcpu, +static u64 reset_bcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd) { vcpu->arch.vcpu_debug_state.dbg_bcr[rd->CRm] = rd->val; + return rd->val; } static bool trap_wvr(struct kvm_vcpu *vcpu, @@ -613,10 +615,11 @@ static int get_wvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, return 0; } -static void reset_wvr(struct kvm_vcpu *vcpu, +static u64 reset_wvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd) { vcpu->arch.vcpu_debug_state.dbg_wvr[rd->CRm] = rd->val; + return rd->val; } static bool trap_wcr(struct kvm_vcpu *vcpu, @@ -649,25 +652,28 @@ static int get_wcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, return 0; } -static void reset_wcr(struct kvm_vcpu *vcpu, +static u64 reset_wcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd) { vcpu->arch.vcpu_debug_state.dbg_wcr[rd->CRm] = rd->val; + return rd->val; } -static void reset_amair_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +static u64 reset_amair_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { u64 amair = read_sysreg(amair_el1); vcpu_write_sys_reg(vcpu, amair, AMAIR_EL1); + return amair; } -static void reset_actlr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +static u64 reset_actlr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { u64 actlr = read_sysreg(actlr_el1); vcpu_write_sys_reg(vcpu, actlr, ACTLR_EL1); + return actlr; } -static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +static u64 reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { u64 mpidr; @@ -681,7 +687,10 @@ static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) mpidr = (vcpu->vcpu_id & 0x0f) << MPIDR_LEVEL_SHIFT(0); mpidr |= ((vcpu->vcpu_id >> 4) & 0xff) << MPIDR_LEVEL_SHIFT(1); mpidr |= ((vcpu->vcpu_id >> 12) & 0xff) << MPIDR_LEVEL_SHIFT(2); - vcpu_write_sys_reg(vcpu, (1ULL << 31) | mpidr, MPIDR_EL1); + mpidr |= (1ULL << 31); + vcpu_write_sys_reg(vcpu, mpidr, MPIDR_EL1); + + return mpidr; } static unsigned int pmu_visibility(const struct kvm_vcpu *vcpu, @@ -693,13 +702,13 @@ static unsigned int pmu_visibility(const struct kvm_vcpu *vcpu, return REG_HIDDEN; } -static void reset_pmu_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +static u64 reset_pmu_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { u64 n, mask = BIT(ARMV8_PMU_CYCLE_IDX); /* No PMU available, any PMU reg may UNDEF... */ if (!kvm_arm_support_pmu_v3()) - return; + return 0; n = read_sysreg(pmcr_el0) >> ARMV8_PMU_PMCR_N_SHIFT; n &= ARMV8_PMU_PMCR_N_MASK; @@ -708,33 +717,41 @@ static void reset_pmu_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) reset_unknown(vcpu, r); __vcpu_sys_reg(vcpu, r->reg) &= mask; + + return __vcpu_sys_reg(vcpu, r->reg); } -static void reset_pmevcntr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +static u64 reset_pmevcntr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { reset_unknown(vcpu, r); __vcpu_sys_reg(vcpu, r->reg) &= GENMASK(31, 0); + + return __vcpu_sys_reg(vcpu, r->reg); } -static void reset_pmevtyper(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +static u64 reset_pmevtyper(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { reset_unknown(vcpu, r); __vcpu_sys_reg(vcpu, r->reg) &= ARMV8_PMU_EVTYPE_MASK; + + return __vcpu_sys_reg(vcpu, r->reg); } -static void reset_pmselr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +static u64 reset_pmselr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { reset_unknown(vcpu, r); __vcpu_sys_reg(vcpu, r->reg) &= ARMV8_PMU_COUNTER_MASK; + + return __vcpu_sys_reg(vcpu, r->reg); } -static void reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +static u64 reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { u64 pmcr; /* No PMU available, PMCR_EL0 may UNDEF... */ if (!kvm_arm_support_pmu_v3()) - return; + return 0; /* Only preserve PMCR_EL0.N, and reset the rest to 0 */ pmcr = read_sysreg(pmcr_el0) & (ARMV8_PMU_PMCR_N_MASK << ARMV8_PMU_PMCR_N_SHIFT); @@ -742,6 +759,8 @@ static void reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) pmcr |= ARMV8_PMU_PMCR_LC; __vcpu_sys_reg(vcpu, r->reg) = pmcr; + + return __vcpu_sys_reg(vcpu, r->reg); } static bool check_pmu_access_disabled(struct kvm_vcpu *vcpu, u64 flags) @@ -1209,7 +1228,8 @@ static u8 pmuver_to_perfmon(u8 pmuver) } /* Read a sanitised cpufeature ID register by sys_reg_desc */ -static u64 read_id_reg(const struct kvm_vcpu *vcpu, struct sys_reg_desc const *r) +static u64 __kvm_read_sanitised_id_reg(const struct kvm_vcpu *vcpu, + const struct sys_reg_desc *r) { u32 id = reg_to_encoding(r); u64 val; @@ -1280,6 +1300,17 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu, struct sys_reg_desc const *r return val; } +static u64 kvm_read_sanitised_id_reg(struct kvm_vcpu *vcpu, + const struct sys_reg_desc *r) +{ + return __kvm_read_sanitised_id_reg(vcpu, r); +} + +static u64 read_id_reg(const struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +{ + return __kvm_read_sanitised_id_reg(vcpu, r); +} + static unsigned int id_visibility(const struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { @@ -1530,7 +1561,7 @@ static bool access_clidr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, * Fabricate a CLIDR_EL1 value instead of using the real value, which can vary * by the physical CPU which the vcpu currently resides in. */ -static void reset_clidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +static u64 reset_clidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { u64 ctr_el0 = read_sanitised_ftr_reg(SYS_CTR_EL0); u64 clidr; @@ -1578,6 +1609,8 @@ static void reset_clidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) clidr |= 2 << CLIDR_TTYPE_SHIFT(loc); __vcpu_sys_reg(vcpu, r->reg) = clidr; + + return __vcpu_sys_reg(vcpu, r->reg); } static int set_clidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, @@ -1677,6 +1710,17 @@ static unsigned int elx2_visibility(const struct kvm_vcpu *vcpu, .visibility = elx2_visibility, \ } +/* + * Since reset() callback and field val are not used for idregs, they will be + * used for specific purposes for idregs. + * The reset() would return KVM sanitised register value. The value would be the + * same as the host kernel sanitised value if there is no KVM sanitisation. + * The val would be used as a mask indicating writable fields for the idreg. + * Only bits with 1 are writable from userspace. This mask might not be + * necessary in the future whenever all ID registers are enabled as writable + * from userspace. + */ + /* sys_reg_desc initialiser for known cpufeature ID registers */ #define ID_SANITISED(name) { \ SYS_DESC(SYS_##name), \ @@ -1684,6 +1728,8 @@ static unsigned int elx2_visibility(const struct kvm_vcpu *vcpu, .get_user = get_id_reg, \ .set_user = set_id_reg, \ .visibility = id_visibility, \ + .reset = kvm_read_sanitised_id_reg, \ + .val = 0, \ } /* sys_reg_desc initialiser for known cpufeature ID registers */ @@ -1693,6 +1739,8 @@ static unsigned int elx2_visibility(const struct kvm_vcpu *vcpu, .get_user = get_id_reg, \ .set_user = set_id_reg, \ .visibility = aa32_id_visibility, \ + .reset = kvm_read_sanitised_id_reg, \ + .val = 0, \ } /* @@ -1705,7 +1753,9 @@ static unsigned int elx2_visibility(const struct kvm_vcpu *vcpu, .access = access_id_reg, \ .get_user = get_id_reg, \ .set_user = set_id_reg, \ - .visibility = raz_visibility \ + .visibility = raz_visibility, \ + .reset = kvm_read_sanitised_id_reg, \ + .val = 0, \ } /* @@ -1719,6 +1769,8 @@ static unsigned int elx2_visibility(const struct kvm_vcpu *vcpu, .get_user = get_id_reg, \ .set_user = set_id_reg, \ .visibility = raz_visibility, \ + .reset = kvm_read_sanitised_id_reg, \ + .val = 0, \ } static bool access_sp_el1(struct kvm_vcpu *vcpu, @@ -3055,19 +3107,21 @@ id_to_sys_reg_desc(struct kvm_vcpu *vcpu, u64 id, */ #define FUNCTION_INVARIANT(reg) \ - static void get_##reg(struct kvm_vcpu *v, \ + static u64 get_##reg(struct kvm_vcpu *v, \ const struct sys_reg_desc *r) \ { \ ((struct sys_reg_desc *)r)->val = read_sysreg(reg); \ + return ((struct sys_reg_desc *)r)->val; \ } FUNCTION_INVARIANT(midr_el1) FUNCTION_INVARIANT(revidr_el1) FUNCTION_INVARIANT(aidr_el1) -static void get_ctr_el0(struct kvm_vcpu *v, const struct sys_reg_desc *r) +static u64 get_ctr_el0(struct kvm_vcpu *v, const struct sys_reg_desc *r) { ((struct sys_reg_desc *)r)->val = read_sanitised_ftr_reg(SYS_CTR_EL0); + return ((struct sys_reg_desc *)r)->val; } /* ->val is filled in by kvm_sys_reg_table_init() */ diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h index 6b11f2cc7146..63bca7521dfd 100644 --- a/arch/arm64/kvm/sys_regs.h +++ b/arch/arm64/kvm/sys_regs.h @@ -64,13 +64,16 @@ struct sys_reg_desc { struct sys_reg_params *, const struct sys_reg_desc *); - /* Initialization for vcpu. */ - void (*reset)(struct kvm_vcpu *, const struct sys_reg_desc *); + /* + * Initialization for vcpu. Return initialized value, or KVM + * sanitized value for ID registers. + */ + u64 (*reset)(struct kvm_vcpu *, const struct sys_reg_desc *); /* Index into sys_reg[], or 0 if we don't need to save it. */ int reg; - /* Value (usually reset value) */ + /* Value (usually reset value), or write mask for idregs */ u64 val; /* Custom get/set_user functions, fallback to generic if NULL */ @@ -123,19 +126,21 @@ static inline bool read_zero(struct kvm_vcpu *vcpu, } /* Reset functions */ -static inline void reset_unknown(struct kvm_vcpu *vcpu, +static inline u64 reset_unknown(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) = 0x1de7ec7edbadc0deULL; + return __vcpu_sys_reg(vcpu, r->reg); } -static inline void reset_val(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) +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; + return __vcpu_sys_reg(vcpu, r->reg); } static inline unsigned int sysreg_visibility(const struct kvm_vcpu *vcpu, |