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@xxxxxxxxx>
> ---
> 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
