| Message ID | 20211012043535.500493-3-reijiw@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Make CPU ID registers writable by userspace | expand |
On Mon, Oct 11, 2021 at 09:35:12PM -0700, Reiji Watanabe wrote: > Extend sys_regs[] of kvm_cpu_context for ID registers and save ID > registers' sanitized value in the array for the vCPU at the first > vCPU reset. Use the saved ones when ID registers are read by > userspace (via KVM_GET_ONE_REG) or the guest. > > Signed-off-by: Reiji Watanabe <reijiw@google.com> > --- > arch/arm64/include/asm/kvm_host.h | 10 ++++++++++ > arch/arm64/kvm/sys_regs.c | 26 ++++++++++++++++++-------- > 2 files changed, 28 insertions(+), 8 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index 9b5e7a3b6011..0cd351099adf 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -145,6 +145,14 @@ struct kvm_vcpu_fault_info { > u64 disr_el1; /* Deferred [SError] Status Register */ > }; > > +/* > + * (Op0, Op1, CRn, CRm, Op2) of ID registers is (3, 0, 0, crm, op2), > + * where 0<=crm<8, 0<=op2<8. crm is 4 bits, so this should be 0 <= crm < 16 and... > + */ > +#define KVM_ARM_ID_REG_MAX_NUM 64 ...this should be 128. Or am I missing something? > +#define IDREG_IDX(id) ((sys_reg_CRm(id) << 3) | sys_reg_Op2(id)) > +#define IDREG_SYS_IDX(id) (ID_REG_BASE + IDREG_IDX(id)) > + > enum vcpu_sysreg { > __INVALID_SYSREG__, /* 0 is reserved as an invalid value */ > MPIDR_EL1, /* MultiProcessor Affinity Register */ > @@ -209,6 +217,8 @@ enum vcpu_sysreg { > CNTP_CVAL_EL0, > CNTP_CTL_EL0, > > + ID_REG_BASE, > + ID_REG_END = ID_REG_BASE + KVM_ARM_ID_REG_MAX_NUM - 1, > /* Memory Tagging Extension registers */ > RGSR_EL1, /* Random Allocation Tag Seed Register */ > GCR_EL1, /* Tag Control Register */ > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > index 1d46e185f31e..72ca518e7944 100644 > --- a/arch/arm64/kvm/sys_regs.c > +++ b/arch/arm64/kvm/sys_regs.c > @@ -273,7 +273,7 @@ static bool trap_loregion(struct kvm_vcpu *vcpu, > struct sys_reg_params *p, > const struct sys_reg_desc *r) > { > - u64 val = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); > + u64 val = __vcpu_sys_reg(vcpu, IDREG_SYS_IDX(SYS_ID_AA64MMFR1_EL1)); > u32 sr = reg_to_encoding(r); > > if (!(val & (0xfUL << ID_AA64MMFR1_LOR_SHIFT))) { > @@ -1059,12 +1059,11 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu, > return true; > } > > -/* 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, bool raz) > { > u32 id = reg_to_encoding(r); > - u64 val = raz ? 0 : read_sanitised_ftr_reg(id); > + u64 val = raz ? 0 : __vcpu_sys_reg(vcpu, IDREG_SYS_IDX(id)); > > switch (id) { > case SYS_ID_AA64PFR0_EL1: > @@ -1174,6 +1173,16 @@ static unsigned int sve_visibility(const struct kvm_vcpu *vcpu, > return REG_HIDDEN; > } > > +static void reset_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd) Since not all ID registers will use this, then maybe name it reset_sanitised_id_reg? > +{ > + u32 id = reg_to_encoding(rd); > + > + if (vcpu_has_reset_once(vcpu)) > + return; Ah, I see my kvm_vcpu_initialized() won't work since vcpu->arch.target is set before the first reset. While vcpu->arch.target is only being used like a "is_initialized" boolean at this time, I guess we better keep it in case we ever want to implement CPU models (which this series gets us a step closer to). > + > + __vcpu_sys_reg(vcpu, IDREG_SYS_IDX(id)) = read_sanitised_ftr_reg(id); > +} > + > static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu, > const struct sys_reg_desc *rd, > const struct kvm_one_reg *reg, void __user *uaddr) > @@ -1219,9 +1228,7 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu, > /* > * cpufeature ID register user accessors > * > - * For now, these registers are immutable for userspace, so no values > - * are stored, and for set_id_reg() we don't allow the effective value > - * to be changed. > + * We don't allow the effective value to be changed. > */ > static int __get_id_reg(const struct kvm_vcpu *vcpu, > const struct sys_reg_desc *rd, void __user *uaddr, > @@ -1375,6 +1382,7 @@ static unsigned int mte_visibility(const struct kvm_vcpu *vcpu, > #define ID_SANITISED(name) { \ > SYS_DESC(SYS_##name), \ > .access = access_id_reg, \ > + .reset = reset_id_reg, \ > .get_user = get_id_reg, \ > .set_user = set_id_reg, \ > .visibility = id_visibility, \ > @@ -1830,8 +1838,10 @@ static bool trap_dbgdidr(struct kvm_vcpu *vcpu, > if (p->is_write) { > return ignore_write(vcpu, p); > } else { > - u64 dfr = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1); > - u64 pfr = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1); > + u64 dfr = __vcpu_sys_reg(vcpu, > + IDREG_SYS_IDX(SYS_ID_AA64DFR0_EL1)); > + u64 pfr = __vcpu_sys_reg(vcpu, > + IDREG_SYS_IDX(SYS_ID_AA64PFR0_EL1)); Please avoid these ugly line breaks when we're well under Linux's max length, which is 100. > u32 el3 = !!cpuid_feature_extract_unsigned_field(pfr, ID_AA64PFR0_EL3_SHIFT); > > p->regval = ((((dfr >> ID_AA64DFR0_WRPS_SHIFT) & 0xf) << 28) | > -- > 2.33.0.882.g93a45727a2-goog > Thanks, drew
On Fri, Oct 15, 2021 at 6:09 AM Andrew Jones <drjones@redhat.com> wrote: > > On Mon, Oct 11, 2021 at 09:35:12PM -0700, Reiji Watanabe wrote: > > Extend sys_regs[] of kvm_cpu_context for ID registers and save ID > > registers' sanitized value in the array for the vCPU at the first > > vCPU reset. Use the saved ones when ID registers are read by > > userspace (via KVM_GET_ONE_REG) or the guest. > > > > Signed-off-by: Reiji Watanabe <reijiw@google.com> > > --- > > arch/arm64/include/asm/kvm_host.h | 10 ++++++++++ > > arch/arm64/kvm/sys_regs.c | 26 ++++++++++++++++++-------- > > 2 files changed, 28 insertions(+), 8 deletions(-) > > > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > > index 9b5e7a3b6011..0cd351099adf 100644 > > --- a/arch/arm64/include/asm/kvm_host.h > > +++ b/arch/arm64/include/asm/kvm_host.h > > @@ -145,6 +145,14 @@ struct kvm_vcpu_fault_info { > > u64 disr_el1; /* Deferred [SError] Status Register */ > > }; > > > > +/* > > + * (Op0, Op1, CRn, CRm, Op2) of ID registers is (3, 0, 0, crm, op2), > > + * where 0<=crm<8, 0<=op2<8. > > crm is 4 bits, so this should be 0 <= crm < 16 and... > > > + */ > > +#define KVM_ARM_ID_REG_MAX_NUM 64 > > ...this should be 128. Or am I missing something? Registers with (3, 0, 0, 0<=crm<8, op2) are defined/allocated including reserved (RAZ) ones (please see Table D12-2 in ARM DDI 0487G.b), and the code supports those only for now. I understand that registers with crm >= 8 could be defined in the future (I'm not so sure if they will be really ID registers though), but then we can include them later as needed. > > +#define IDREG_IDX(id) ((sys_reg_CRm(id) << 3) | sys_reg_Op2(id)) > > +#define IDREG_SYS_IDX(id) (ID_REG_BASE + IDREG_IDX(id)) > > + > > enum vcpu_sysreg { > > __INVALID_SYSREG__, /* 0 is reserved as an invalid value */ > > MPIDR_EL1, /* MultiProcessor Affinity Register */ > > @@ -209,6 +217,8 @@ enum vcpu_sysreg { > > CNTP_CVAL_EL0, > > CNTP_CTL_EL0, > > > > + ID_REG_BASE, > > + ID_REG_END = ID_REG_BASE + KVM_ARM_ID_REG_MAX_NUM - 1, > > /* Memory Tagging Extension registers */ > > RGSR_EL1, /* Random Allocation Tag Seed Register */ > > GCR_EL1, /* Tag Control Register */ > > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > > index 1d46e185f31e..72ca518e7944 100644 > > --- a/arch/arm64/kvm/sys_regs.c > > +++ b/arch/arm64/kvm/sys_regs.c > > @@ -273,7 +273,7 @@ static bool trap_loregion(struct kvm_vcpu *vcpu, > > struct sys_reg_params *p, > > const struct sys_reg_desc *r) > > { > > - u64 val = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); > > + u64 val = __vcpu_sys_reg(vcpu, IDREG_SYS_IDX(SYS_ID_AA64MMFR1_EL1)); > > u32 sr = reg_to_encoding(r); > > > > if (!(val & (0xfUL << ID_AA64MMFR1_LOR_SHIFT))) { > > @@ -1059,12 +1059,11 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu, > > return true; > > } > > > > -/* 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, bool raz) > > { > > u32 id = reg_to_encoding(r); > > - u64 val = raz ? 0 : read_sanitised_ftr_reg(id); > > + u64 val = raz ? 0 : __vcpu_sys_reg(vcpu, IDREG_SYS_IDX(id)); > > > > switch (id) { > > case SYS_ID_AA64PFR0_EL1: > > @@ -1174,6 +1173,16 @@ static unsigned int sve_visibility(const struct kvm_vcpu *vcpu, > > return REG_HIDDEN; > > } > > > > +static void reset_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd) > > Since not all ID registers will use this, then maybe name it > reset_sanitised_id_reg? Thank you for the suggestion. I named it 'reset_id_reg' according to the naming conventions of set_id_reg, get_id_reg, and access_id_reg which are used for the same set of ID registers (ID_SANITISED ones) as reset_id_reg. I would think it's better to use consistent names for all of them. So, I am a bit reluctant to change only the name of reset_id_reg. What do you think about the names of those other three functions ? > > +{ > > + u32 id = reg_to_encoding(rd); > > + > > + if (vcpu_has_reset_once(vcpu)) > > + return; > > Ah, I see my kvm_vcpu_initialized() won't work since vcpu->arch.target is > set before the first reset. While vcpu->arch.target is only being used > like a "is_initialized" boolean at this time, I guess we better keep it > in case we ever want to implement CPU models (which this series gets us a > step closer to). Thank you for sharing your thoughts and I agree with you. > > + > > + __vcpu_sys_reg(vcpu, IDREG_SYS_IDX(id)) = read_sanitised_ftr_reg(id); > > +} > > + > > static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu, > > const struct sys_reg_desc *rd, > > const struct kvm_one_reg *reg, void __user *uaddr) > > @@ -1219,9 +1228,7 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu, > > /* > > * cpufeature ID register user accessors > > * > > - * For now, these registers are immutable for userspace, so no values > > - * are stored, and for set_id_reg() we don't allow the effective value > > - * to be changed. > > + * We don't allow the effective value to be changed. > > */ > > static int __get_id_reg(const struct kvm_vcpu *vcpu, > > const struct sys_reg_desc *rd, void __user *uaddr, > > @@ -1375,6 +1382,7 @@ static unsigned int mte_visibility(const struct kvm_vcpu *vcpu, > > #define ID_SANITISED(name) { \ > > SYS_DESC(SYS_##name), \ > > .access = access_id_reg, \ > > + .reset = reset_id_reg, \ > > .get_user = get_id_reg, \ > > .set_user = set_id_reg, \ > > .visibility = id_visibility, \ > > @@ -1830,8 +1838,10 @@ static bool trap_dbgdidr(struct kvm_vcpu *vcpu, > > if (p->is_write) { > > return ignore_write(vcpu, p); > > } else { > > - u64 dfr = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1); > > - u64 pfr = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1); > > + u64 dfr = __vcpu_sys_reg(vcpu, > > + IDREG_SYS_IDX(SYS_ID_AA64DFR0_EL1)); > > + u64 pfr = __vcpu_sys_reg(vcpu, > > + IDREG_SYS_IDX(SYS_ID_AA64PFR0_EL1)); > > Please avoid these ugly line breaks when we're well under Linux's max > length, which is 100. Yes, I will fix them (as well as all other similar line breaks for other patches in my series). Thanks, Reiji
On Sat, Oct 16, 2021 at 05:42:59PM -0700, Reiji Watanabe wrote: > On Fri, Oct 15, 2021 at 6:09 AM Andrew Jones <drjones@redhat.com> wrote: > > > > On Mon, Oct 11, 2021 at 09:35:12PM -0700, Reiji Watanabe wrote: > > > Extend sys_regs[] of kvm_cpu_context for ID registers and save ID > > > registers' sanitized value in the array for the vCPU at the first > > > vCPU reset. Use the saved ones when ID registers are read by > > > userspace (via KVM_GET_ONE_REG) or the guest. > > > > > > Signed-off-by: Reiji Watanabe <reijiw@google.com> > > > --- > > > arch/arm64/include/asm/kvm_host.h | 10 ++++++++++ > > > arch/arm64/kvm/sys_regs.c | 26 ++++++++++++++++++-------- > > > 2 files changed, 28 insertions(+), 8 deletions(-) > > > > > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > > > index 9b5e7a3b6011..0cd351099adf 100644 > > > --- a/arch/arm64/include/asm/kvm_host.h > > > +++ b/arch/arm64/include/asm/kvm_host.h > > > @@ -145,6 +145,14 @@ struct kvm_vcpu_fault_info { > > > u64 disr_el1; /* Deferred [SError] Status Register */ > > > }; > > > > > > +/* > > > + * (Op0, Op1, CRn, CRm, Op2) of ID registers is (3, 0, 0, crm, op2), > > > + * where 0<=crm<8, 0<=op2<8. > > > > crm is 4 bits, so this should be 0 <= crm < 16 and... > > > > > + */ > > > +#define KVM_ARM_ID_REG_MAX_NUM 64 > > > > ...this should be 128. Or am I missing something? > > Registers with (3, 0, 0, 0<=crm<8, op2) are defined/allocated including > reserved (RAZ) ones (please see Table D12-2 in ARM DDI 0487G.b), > and the code supports those only for now. > > I understand that registers with crm >= 8 could be defined in the future > (I'm not so sure if they will be really ID registers though), > but then we can include them later as needed. Oh, I see. Thanks. Looking at the table I see CRm=0,op2={1,2,3,4,7} are also missing, but it certainly doesn't matter that we allocate a few unused entries, especially since we also allocate entries for all the RAZ ones. > > > > +#define IDREG_IDX(id) ((sys_reg_CRm(id) << 3) | sys_reg_Op2(id)) > > > +#define IDREG_SYS_IDX(id) (ID_REG_BASE + IDREG_IDX(id)) > > > + > > > enum vcpu_sysreg { > > > __INVALID_SYSREG__, /* 0 is reserved as an invalid value */ > > > MPIDR_EL1, /* MultiProcessor Affinity Register */ > > > @@ -209,6 +217,8 @@ enum vcpu_sysreg { > > > CNTP_CVAL_EL0, > > > CNTP_CTL_EL0, > > > > > > + ID_REG_BASE, > > > + ID_REG_END = ID_REG_BASE + KVM_ARM_ID_REG_MAX_NUM - 1, > > > /* Memory Tagging Extension registers */ > > > RGSR_EL1, /* Random Allocation Tag Seed Register */ > > > GCR_EL1, /* Tag Control Register */ > > > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > > > index 1d46e185f31e..72ca518e7944 100644 > > > --- a/arch/arm64/kvm/sys_regs.c > > > +++ b/arch/arm64/kvm/sys_regs.c > > > @@ -273,7 +273,7 @@ static bool trap_loregion(struct kvm_vcpu *vcpu, > > > struct sys_reg_params *p, > > > const struct sys_reg_desc *r) > > > { > > > - u64 val = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); > > > + u64 val = __vcpu_sys_reg(vcpu, IDREG_SYS_IDX(SYS_ID_AA64MMFR1_EL1)); > > > u32 sr = reg_to_encoding(r); > > > > > > if (!(val & (0xfUL << ID_AA64MMFR1_LOR_SHIFT))) { > > > @@ -1059,12 +1059,11 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu, > > > return true; > > > } > > > > > > -/* 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, bool raz) > > > { > > > u32 id = reg_to_encoding(r); > > > - u64 val = raz ? 0 : read_sanitised_ftr_reg(id); > > > + u64 val = raz ? 0 : __vcpu_sys_reg(vcpu, IDREG_SYS_IDX(id)); > > > > > > switch (id) { > > > case SYS_ID_AA64PFR0_EL1: > > > @@ -1174,6 +1173,16 @@ static unsigned int sve_visibility(const struct kvm_vcpu *vcpu, > > > return REG_HIDDEN; > > > } > > > > > > +static void reset_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd) > > > > Since not all ID registers will use this, then maybe name it > > reset_sanitised_id_reg? > > Thank you for the suggestion. > > I named it 'reset_id_reg' according to the naming conventions of > set_id_reg, get_id_reg, and access_id_reg which are used for the same > set of ID registers (ID_SANITISED ones) as reset_id_reg. > I would think it's better to use consistent names for all of them. > So, I am a bit reluctant to change only the name of reset_id_reg. > > What do you think about the names of those other three functions ? I think I like the shorter names, so please disregard my suggestion. Thanks, drew
> > > > +static void reset_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd) > > > > > > Since not all ID registers will use this, then maybe name it > > > reset_sanitised_id_reg? > > > > Thank you for the suggestion. > > > > I named it 'reset_id_reg' according to the naming conventions of > > set_id_reg, get_id_reg, and access_id_reg which are used for the same > > set of ID registers (ID_SANITISED ones) as reset_id_reg. > > I would think it's better to use consistent names for all of them. > > So, I am a bit reluctant to change only the name of reset_id_reg. > > > > What do you think about the names of those other three functions ? > > I think I like the shorter names, so please disregard my suggestion. Thank you for the confirmation. I will keep those names as they are. Regards, Reiji
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 9b5e7a3b6011..0cd351099adf 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -145,6 +145,14 @@ struct kvm_vcpu_fault_info { u64 disr_el1; /* Deferred [SError] Status Register */ }; +/* + * (Op0, Op1, CRn, CRm, Op2) of ID registers is (3, 0, 0, crm, op2), + * where 0<=crm<8, 0<=op2<8. + */ +#define KVM_ARM_ID_REG_MAX_NUM 64 +#define IDREG_IDX(id) ((sys_reg_CRm(id) << 3) | sys_reg_Op2(id)) +#define IDREG_SYS_IDX(id) (ID_REG_BASE + IDREG_IDX(id)) + enum vcpu_sysreg { __INVALID_SYSREG__, /* 0 is reserved as an invalid value */ MPIDR_EL1, /* MultiProcessor Affinity Register */ @@ -209,6 +217,8 @@ enum vcpu_sysreg { CNTP_CVAL_EL0, CNTP_CTL_EL0, + ID_REG_BASE, + ID_REG_END = ID_REG_BASE + KVM_ARM_ID_REG_MAX_NUM - 1, /* Memory Tagging Extension registers */ RGSR_EL1, /* Random Allocation Tag Seed Register */ GCR_EL1, /* Tag Control Register */ diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 1d46e185f31e..72ca518e7944 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -273,7 +273,7 @@ static bool trap_loregion(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { - u64 val = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); + u64 val = __vcpu_sys_reg(vcpu, IDREG_SYS_IDX(SYS_ID_AA64MMFR1_EL1)); u32 sr = reg_to_encoding(r); if (!(val & (0xfUL << ID_AA64MMFR1_LOR_SHIFT))) { @@ -1059,12 +1059,11 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu, return true; } -/* 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, bool raz) { u32 id = reg_to_encoding(r); - u64 val = raz ? 0 : read_sanitised_ftr_reg(id); + u64 val = raz ? 0 : __vcpu_sys_reg(vcpu, IDREG_SYS_IDX(id)); switch (id) { case SYS_ID_AA64PFR0_EL1: @@ -1174,6 +1173,16 @@ static unsigned int sve_visibility(const struct kvm_vcpu *vcpu, return REG_HIDDEN; } +static void reset_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd) +{ + u32 id = reg_to_encoding(rd); + + if (vcpu_has_reset_once(vcpu)) + return; + + __vcpu_sys_reg(vcpu, IDREG_SYS_IDX(id)) = read_sanitised_ftr_reg(id); +} + static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, const struct kvm_one_reg *reg, void __user *uaddr) @@ -1219,9 +1228,7 @@ static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu, /* * cpufeature ID register user accessors * - * For now, these registers are immutable for userspace, so no values - * are stored, and for set_id_reg() we don't allow the effective value - * to be changed. + * We don't allow the effective value to be changed. */ static int __get_id_reg(const struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, void __user *uaddr, @@ -1375,6 +1382,7 @@ static unsigned int mte_visibility(const struct kvm_vcpu *vcpu, #define ID_SANITISED(name) { \ SYS_DESC(SYS_##name), \ .access = access_id_reg, \ + .reset = reset_id_reg, \ .get_user = get_id_reg, \ .set_user = set_id_reg, \ .visibility = id_visibility, \ @@ -1830,8 +1838,10 @@ static bool trap_dbgdidr(struct kvm_vcpu *vcpu, if (p->is_write) { return ignore_write(vcpu, p); } else { - u64 dfr = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1); - u64 pfr = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1); + u64 dfr = __vcpu_sys_reg(vcpu, + IDREG_SYS_IDX(SYS_ID_AA64DFR0_EL1)); + u64 pfr = __vcpu_sys_reg(vcpu, + IDREG_SYS_IDX(SYS_ID_AA64PFR0_EL1)); u32 el3 = !!cpuid_feature_extract_unsigned_field(pfr, ID_AA64PFR0_EL3_SHIFT); p->regval = ((((dfr >> ID_AA64DFR0_WRPS_SHIFT) & 0xf) << 28) |
Extend sys_regs[] of kvm_cpu_context for ID registers and save ID registers' sanitized value in the array for the vCPU at the first vCPU reset. Use the saved ones when ID registers are read by userspace (via KVM_GET_ONE_REG) or the guest. Signed-off-by: Reiji Watanabe <reijiw@google.com> --- arch/arm64/include/asm/kvm_host.h | 10 ++++++++++ arch/arm64/kvm/sys_regs.c | 26 ++++++++++++++++++-------- 2 files changed, 28 insertions(+), 8 deletions(-)