| Message ID | 20230526221712.317287-15-oliver.upton@linux.dev (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Handle PSCI calls in userspace | expand |
Hi Oliver, On Fri, May 26, 2023 at 10:17:05PM +0000, Oliver Upton wrote: > Add an extremely barebones implementation for handling PSCI, where the > only supported call is PSCI_VERSION. > > Signed-off-by: Oliver Upton <oliver.upton@linux.dev> > --- > Makefile | 4 +- > arm/aarch32/kvm-cpu.c | 5 +++ > arm/aarch64/include/asm/smccc.h | 65 +++++++++++++++++++++++++++++++++ > arm/aarch64/kvm-cpu.c | 14 +++++++ > arm/aarch64/kvm.c | 2 + > arm/aarch64/psci.c | 36 ++++++++++++++++++ > arm/aarch64/smccc.c | 45 +++++++++++++++++++++++ > arm/kvm-cpu.c | 5 --- > 8 files changed, 170 insertions(+), 6 deletions(-) > create mode 100644 arm/aarch64/include/asm/smccc.h > create mode 100644 arm/aarch64/psci.c > create mode 100644 arm/aarch64/smccc.c > > diff --git a/Makefile b/Makefile > index ed2414bd8d1a..fa4836aebc5e 100644 > --- a/Makefile > +++ b/Makefile > @@ -190,8 +190,10 @@ ifeq ($(ARCH), arm64) > OBJS += arm/aarch64/arm-cpu.o > OBJS += arm/aarch64/kvm-cpu.o > OBJS += arm/aarch64/kvm.o > - OBJS += arm/aarch64/pvtime.o > OBJS += arm/aarch64/pmu.o > + OBJS += arm/aarch64/psci.o > + OBJS += arm/aarch64/pvtime.o > + OBJS += arm/aarch64/smccc.o > ARCH_INCLUDE := $(HDRS_ARM_COMMON) > ARCH_INCLUDE += -Iarm/aarch64/include > > diff --git a/arm/aarch32/kvm-cpu.c b/arm/aarch32/kvm-cpu.c > index 95fb1da5ba3d..1063b9e5b6a9 100644 > --- a/arm/aarch32/kvm-cpu.c > +++ b/arm/aarch32/kvm-cpu.c > @@ -130,3 +130,8 @@ void kvm_cpu__show_registers(struct kvm_cpu *vcpu) > die("KVM_GET_ONE_REG failed (LR_svc)"); > dprintf(debug_fd, " LR_svc: 0x%x\n", data); > } > + > +bool kvm_cpu__handle_exit(struct kvm_cpu *vcpu) > +{ > + return false; > +} > diff --git a/arm/aarch64/include/asm/smccc.h b/arm/aarch64/include/asm/smccc.h > new file mode 100644 > index 000000000000..c1be21a7d6f6 > --- /dev/null > +++ b/arm/aarch64/include/asm/smccc.h > @@ -0,0 +1,65 @@ > +#ifndef __ARM_SMCCC_H__ > +#define __ARM_SMCCC_H__ > + > +#include "kvm/kvm-cpu.h" > + > +#include <linux/arm-smccc.h> > +#include <linux/types.h> > + > +static inline bool smccc_is_64bit(struct kvm_cpu *vcpu) > +{ > + return ARM_SMCCC_IS_64(vcpu->kvm_run->hypercall.nr); > +} > + > +static inline bool smccc_calling_conv_allowed(struct kvm_cpu *vcpu, u32 fn) > +{ > + return !(vcpu->kvm->cfg.arch.aarch32_guest && ARM_SMCCC_IS_64(fn)); > +} > + > +static inline u64 smccc_get_arg(struct kvm_cpu *vcpu, u8 arg) > +{ > + u64 val; > + struct kvm_one_reg reg = { > + .id = ARM64_CORE_REG(regs.regs[arg]), > + .addr = (u64)&val, > + }; > + > + if (ioctl(vcpu->vcpu_fd, KVM_GET_ONE_REG, ®)) > + die_perror("KVM_GET_ONE_REG failed"); > + > + if (!smccc_is_64bit(vcpu)) > + val = (u32)val; > + > + return val; > +} > + > +static inline void smccc_return_result(struct kvm_cpu *vcpu, struct arm_smccc_res *res) > +{ > + unsigned long *vals = (unsigned long *)res; > + unsigned long i; > + > + /* > + * The author was lazy and chose to abuse the layout of struct > + * arm_smccc_res to write a loop set the retvals. > + */ > + for (i = 0; i < sizeof(*res) / sizeof(unsigned long); i++) { > + u64 val = vals[i]; > + struct kvm_one_reg reg = { > + .id = ARM64_CORE_REG(regs.regs[i]), > + .addr = (u64)&val, > + }; > + > + if (!smccc_is_64bit(vcpu)) > + val = (u32)val; > + > + if (ioctl(vcpu->vcpu_fd, KVM_SET_ONE_REG, ®)) > + die_perror("KVM_SET_ONE_REG failed"); > + } > +} > + > +bool handle_hypercall(struct kvm_cpu *vcpu); > +void handle_psci(struct kvm_cpu *vcpu, struct arm_smccc_res *res); > + > +void kvm__setup_smccc(struct kvm *kvm); > + > +#endif /* __ARM_SMCCC_H__ */ > diff --git a/arm/aarch64/kvm-cpu.c b/arm/aarch64/kvm-cpu.c > index 1e5a6cfdaf40..4feed9f41cb0 100644 > --- a/arm/aarch64/kvm-cpu.c > +++ b/arm/aarch64/kvm-cpu.c > @@ -1,3 +1,4 @@ > +#include "asm/smccc.h" > #include "kvm/kvm-cpu.h" > #include "kvm/kvm.h" > #include "kvm/virtio.h" > @@ -261,3 +262,16 @@ void kvm_cpu__show_registers(struct kvm_cpu *vcpu) > die("KVM_GET_ONE_REG failed (lr)"); > dprintf(debug_fd, " LR: 0x%lx\n", data); > } > + > +bool kvm_cpu__handle_exit(struct kvm_cpu *vcpu) > +{ > + struct kvm_run *run = vcpu->kvm_run; > + > + switch (run->exit_reason) { > + case KVM_EXIT_HYPERCALL: > + handle_hypercall(vcpu); > + return true; > + default: > + return false; > + } > +} > diff --git a/arm/aarch64/kvm.c b/arm/aarch64/kvm.c > index 4929ce48843b..ce917ed01349 100644 > --- a/arm/aarch64/kvm.c > +++ b/arm/aarch64/kvm.c > @@ -1,3 +1,4 @@ > +#include "asm/smccc.h" > #include "kvm/kvm.h" > #include "kvm/kvm-cpu.h" > > @@ -165,6 +166,7 @@ static void kvm__arch_enable_mte(struct kvm *kvm) > void __kvm__arm_init(struct kvm *kvm) > { > kvm__arch_enable_mte(kvm); > + kvm__setup_smccc(kvm); > } > > struct kvm_cpu *kvm__arch_mpidr_to_vcpu(struct kvm *kvm, u64 target_mpidr) > diff --git a/arm/aarch64/psci.c b/arm/aarch64/psci.c > new file mode 100644 > index 000000000000..482b9a7442c6 > --- /dev/null > +++ b/arm/aarch64/psci.c > @@ -0,0 +1,36 @@ > +#include "asm/smccc.h" > +#include "kvm/kvm.h" > +#include "kvm/kvm-cpu.h" > +#include "kvm/util.h" > + > +#include <linux/psci.h> > +#include <linux/types.h> > + > +static void psci_features(struct kvm_cpu *vcpu, struct arm_smccc_res *res) > +{ > + u32 arg = smccc_get_arg(vcpu, 1); > + > + res->a0 = PSCI_RET_NOT_SUPPORTED; > + if (!smccc_calling_conv_allowed(vcpu, arg)) > + return; > + > + switch (arg) { > + case ARM_SMCCC_VERSION_FUNC_ID: > + res->a0 = PSCI_RET_SUCCESS; > + break; > + } > +} > + > +void handle_psci(struct kvm_cpu *vcpu, struct arm_smccc_res *res) > +{ > + switch (vcpu->kvm_run->hypercall.nr) { > + case PSCI_0_2_FN_PSCI_VERSION: > + res->a0 = PSCI_VERSION(1, 0); > + break; > + case PSCI_1_0_FN_PSCI_FEATURES: > + psci_features(vcpu, res); > + break; > + default: > + res->a0 = PSCI_RET_NOT_SUPPORTED; > + } > +} > diff --git a/arm/aarch64/smccc.c b/arm/aarch64/smccc.c > new file mode 100644 > index 000000000000..b95077305ffa > --- /dev/null > +++ b/arm/aarch64/smccc.c > @@ -0,0 +1,45 @@ > +#include "asm/smccc.h" > +#include "kvm/kvm.h" > +#include "kvm/kvm-cpu.h" > +#include "kvm/util.h" > + > +#include <linux/types.h> > + > +static void handle_std_call(struct kvm_cpu *vcpu, struct arm_smccc_res *res) > +{ > + u32 fn = vcpu->kvm_run->hypercall.nr; > + > + switch (ARM_SMCCC_FUNC_NUM(fn)) { > + /* PSCI */ > + case 0x00 ... 0x1F: > + handle_psci(vcpu, res); > + break; > + } > +} > + > +bool handle_hypercall(struct kvm_cpu *vcpu) > +{ > + u32 fn = vcpu->kvm_run->hypercall.nr; > + struct arm_smccc_res res = { > + .a0 = SMCCC_RET_NOT_SUPPORTED, > + }; > + > + if (!smccc_calling_conv_allowed(vcpu, fn)) > + goto out; > + > + switch (ARM_SMCCC_OWNER_NUM(fn)) { > + case ARM_SMCCC_OWNER_STANDARD: > + handle_std_call(vcpu, &res); > + break; > + default: I get the following error while compiling (adding a `break;` fixes things): arm/aarch64/smccc.c: In function 'handle_hypercall': arm/aarch64/smccc.c:34:2: error: label at end of compound statement 34 | default: | ^~~~~~~ > + } > + > +out: > + smccc_return_result(vcpu, &res); > + return true; > +} > + > +void kvm__setup_smccc(struct kvm *kvm) > +{ > + > +} > diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c > index 12a366b9b38b..3e383065ddaa 100644 > --- a/arm/kvm-cpu.c > +++ b/arm/kvm-cpu.c > @@ -158,11 +158,6 @@ void kvm_cpu__delete(struct kvm_cpu *vcpu) > free(vcpu); > } > > -bool kvm_cpu__handle_exit(struct kvm_cpu *vcpu) > -{ > - return false; > -} > - > void kvm_cpu__show_page_tables(struct kvm_cpu *vcpu) > { > } Thanks, Joey
diff --git a/Makefile b/Makefile index ed2414bd8d1a..fa4836aebc5e 100644 --- a/Makefile +++ b/Makefile @@ -190,8 +190,10 @@ ifeq ($(ARCH), arm64) OBJS += arm/aarch64/arm-cpu.o OBJS += arm/aarch64/kvm-cpu.o OBJS += arm/aarch64/kvm.o - OBJS += arm/aarch64/pvtime.o OBJS += arm/aarch64/pmu.o + OBJS += arm/aarch64/psci.o + OBJS += arm/aarch64/pvtime.o + OBJS += arm/aarch64/smccc.o ARCH_INCLUDE := $(HDRS_ARM_COMMON) ARCH_INCLUDE += -Iarm/aarch64/include diff --git a/arm/aarch32/kvm-cpu.c b/arm/aarch32/kvm-cpu.c index 95fb1da5ba3d..1063b9e5b6a9 100644 --- a/arm/aarch32/kvm-cpu.c +++ b/arm/aarch32/kvm-cpu.c @@ -130,3 +130,8 @@ void kvm_cpu__show_registers(struct kvm_cpu *vcpu) die("KVM_GET_ONE_REG failed (LR_svc)"); dprintf(debug_fd, " LR_svc: 0x%x\n", data); } + +bool kvm_cpu__handle_exit(struct kvm_cpu *vcpu) +{ + return false; +} diff --git a/arm/aarch64/include/asm/smccc.h b/arm/aarch64/include/asm/smccc.h new file mode 100644 index 000000000000..c1be21a7d6f6 --- /dev/null +++ b/arm/aarch64/include/asm/smccc.h @@ -0,0 +1,65 @@ +#ifndef __ARM_SMCCC_H__ +#define __ARM_SMCCC_H__ + +#include "kvm/kvm-cpu.h" + +#include <linux/arm-smccc.h> +#include <linux/types.h> + +static inline bool smccc_is_64bit(struct kvm_cpu *vcpu) +{ + return ARM_SMCCC_IS_64(vcpu->kvm_run->hypercall.nr); +} + +static inline bool smccc_calling_conv_allowed(struct kvm_cpu *vcpu, u32 fn) +{ + return !(vcpu->kvm->cfg.arch.aarch32_guest && ARM_SMCCC_IS_64(fn)); +} + +static inline u64 smccc_get_arg(struct kvm_cpu *vcpu, u8 arg) +{ + u64 val; + struct kvm_one_reg reg = { + .id = ARM64_CORE_REG(regs.regs[arg]), + .addr = (u64)&val, + }; + + if (ioctl(vcpu->vcpu_fd, KVM_GET_ONE_REG, ®)) + die_perror("KVM_GET_ONE_REG failed"); + + if (!smccc_is_64bit(vcpu)) + val = (u32)val; + + return val; +} + +static inline void smccc_return_result(struct kvm_cpu *vcpu, struct arm_smccc_res *res) +{ + unsigned long *vals = (unsigned long *)res; + unsigned long i; + + /* + * The author was lazy and chose to abuse the layout of struct + * arm_smccc_res to write a loop set the retvals. + */ + for (i = 0; i < sizeof(*res) / sizeof(unsigned long); i++) { + u64 val = vals[i]; + struct kvm_one_reg reg = { + .id = ARM64_CORE_REG(regs.regs[i]), + .addr = (u64)&val, + }; + + if (!smccc_is_64bit(vcpu)) + val = (u32)val; + + if (ioctl(vcpu->vcpu_fd, KVM_SET_ONE_REG, ®)) + die_perror("KVM_SET_ONE_REG failed"); + } +} + +bool handle_hypercall(struct kvm_cpu *vcpu); +void handle_psci(struct kvm_cpu *vcpu, struct arm_smccc_res *res); + +void kvm__setup_smccc(struct kvm *kvm); + +#endif /* __ARM_SMCCC_H__ */ diff --git a/arm/aarch64/kvm-cpu.c b/arm/aarch64/kvm-cpu.c index 1e5a6cfdaf40..4feed9f41cb0 100644 --- a/arm/aarch64/kvm-cpu.c +++ b/arm/aarch64/kvm-cpu.c @@ -1,3 +1,4 @@ +#include "asm/smccc.h" #include "kvm/kvm-cpu.h" #include "kvm/kvm.h" #include "kvm/virtio.h" @@ -261,3 +262,16 @@ void kvm_cpu__show_registers(struct kvm_cpu *vcpu) die("KVM_GET_ONE_REG failed (lr)"); dprintf(debug_fd, " LR: 0x%lx\n", data); } + +bool kvm_cpu__handle_exit(struct kvm_cpu *vcpu) +{ + struct kvm_run *run = vcpu->kvm_run; + + switch (run->exit_reason) { + case KVM_EXIT_HYPERCALL: + handle_hypercall(vcpu); + return true; + default: + return false; + } +} diff --git a/arm/aarch64/kvm.c b/arm/aarch64/kvm.c index 4929ce48843b..ce917ed01349 100644 --- a/arm/aarch64/kvm.c +++ b/arm/aarch64/kvm.c @@ -1,3 +1,4 @@ +#include "asm/smccc.h" #include "kvm/kvm.h" #include "kvm/kvm-cpu.h" @@ -165,6 +166,7 @@ static void kvm__arch_enable_mte(struct kvm *kvm) void __kvm__arm_init(struct kvm *kvm) { kvm__arch_enable_mte(kvm); + kvm__setup_smccc(kvm); } struct kvm_cpu *kvm__arch_mpidr_to_vcpu(struct kvm *kvm, u64 target_mpidr) diff --git a/arm/aarch64/psci.c b/arm/aarch64/psci.c new file mode 100644 index 000000000000..482b9a7442c6 --- /dev/null +++ b/arm/aarch64/psci.c @@ -0,0 +1,36 @@ +#include "asm/smccc.h" +#include "kvm/kvm.h" +#include "kvm/kvm-cpu.h" +#include "kvm/util.h" + +#include <linux/psci.h> +#include <linux/types.h> + +static void psci_features(struct kvm_cpu *vcpu, struct arm_smccc_res *res) +{ + u32 arg = smccc_get_arg(vcpu, 1); + + res->a0 = PSCI_RET_NOT_SUPPORTED; + if (!smccc_calling_conv_allowed(vcpu, arg)) + return; + + switch (arg) { + case ARM_SMCCC_VERSION_FUNC_ID: + res->a0 = PSCI_RET_SUCCESS; + break; + } +} + +void handle_psci(struct kvm_cpu *vcpu, struct arm_smccc_res *res) +{ + switch (vcpu->kvm_run->hypercall.nr) { + case PSCI_0_2_FN_PSCI_VERSION: + res->a0 = PSCI_VERSION(1, 0); + break; + case PSCI_1_0_FN_PSCI_FEATURES: + psci_features(vcpu, res); + break; + default: + res->a0 = PSCI_RET_NOT_SUPPORTED; + } +} diff --git a/arm/aarch64/smccc.c b/arm/aarch64/smccc.c new file mode 100644 index 000000000000..b95077305ffa --- /dev/null +++ b/arm/aarch64/smccc.c @@ -0,0 +1,45 @@ +#include "asm/smccc.h" +#include "kvm/kvm.h" +#include "kvm/kvm-cpu.h" +#include "kvm/util.h" + +#include <linux/types.h> + +static void handle_std_call(struct kvm_cpu *vcpu, struct arm_smccc_res *res) +{ + u32 fn = vcpu->kvm_run->hypercall.nr; + + switch (ARM_SMCCC_FUNC_NUM(fn)) { + /* PSCI */ + case 0x00 ... 0x1F: + handle_psci(vcpu, res); + break; + } +} + +bool handle_hypercall(struct kvm_cpu *vcpu) +{ + u32 fn = vcpu->kvm_run->hypercall.nr; + struct arm_smccc_res res = { + .a0 = SMCCC_RET_NOT_SUPPORTED, + }; + + if (!smccc_calling_conv_allowed(vcpu, fn)) + goto out; + + switch (ARM_SMCCC_OWNER_NUM(fn)) { + case ARM_SMCCC_OWNER_STANDARD: + handle_std_call(vcpu, &res); + break; + default: + } + +out: + smccc_return_result(vcpu, &res); + return true; +} + +void kvm__setup_smccc(struct kvm *kvm) +{ + +} diff --git a/arm/kvm-cpu.c b/arm/kvm-cpu.c index 12a366b9b38b..3e383065ddaa 100644 --- a/arm/kvm-cpu.c +++ b/arm/kvm-cpu.c @@ -158,11 +158,6 @@ void kvm_cpu__delete(struct kvm_cpu *vcpu) free(vcpu); } -bool kvm_cpu__handle_exit(struct kvm_cpu *vcpu) -{ - return false; -} - void kvm_cpu__show_page_tables(struct kvm_cpu *vcpu) { }
Add an extremely barebones implementation for handling PSCI, where the only supported call is PSCI_VERSION. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> --- Makefile | 4 +- arm/aarch32/kvm-cpu.c | 5 +++ arm/aarch64/include/asm/smccc.h | 65 +++++++++++++++++++++++++++++++++ arm/aarch64/kvm-cpu.c | 14 +++++++ arm/aarch64/kvm.c | 2 + arm/aarch64/psci.c | 36 ++++++++++++++++++ arm/aarch64/smccc.c | 45 +++++++++++++++++++++++ arm/kvm-cpu.c | 5 --- 8 files changed, 170 insertions(+), 6 deletions(-) create mode 100644 arm/aarch64/include/asm/smccc.h create mode 100644 arm/aarch64/psci.c create mode 100644 arm/aarch64/smccc.c