From mboxrd@z Thu Jan 1 00:00:00 1970 From: christoffer.dall@linaro.org (Christoffer Dall) Date: Fri, 13 Dec 2013 12:08:34 -0800 Subject: [PATCH v2 2/2] ARM/ARM64: KVM: Forward PSCI SYSTEM_OFF and SYSTEM_RESET to user space In-Reply-To: <1386864747-29006-6-git-send-email-anup.patel@linaro.org> References: <1386864747-29006-1-git-send-email-anup.patel@linaro.org> <1386864747-29006-6-git-send-email-anup.patel@linaro.org> Message-ID: <20131213200834.GB2871@cbox> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Dec 12, 2013 at 09:42:27PM +0530, Anup Patel wrote: > The PSCI SYSTEM_OFF and SYSTEM_RESET functions are system-level > functions hence cannot be fully emulated by the in-kernel PSCI > emulation code. > > To tackle this, we forward PSCI SYSTEM_OFF and SYSTEM_RESET function > calls from vcpu to user space (i.e. QEMU or KVMTOOL) via kvm_run > structure using KVM_EXIT_SYSTEM_EVENT exit reasons. > > Signed-off-by: Anup Patel > Signed-off-by: Pranavkumar Sawargaonkar > --- > arch/arm/include/asm/kvm_psci.h | 2 +- > arch/arm/include/uapi/asm/kvm.h | 2 ++ > arch/arm/kvm/handle_exit.c | 13 +++++++--- > arch/arm/kvm/psci.c | 48 ++++++++++++++++++++++++++++++------- > arch/arm64/include/asm/kvm_psci.h | 2 +- > arch/arm64/include/uapi/asm/kvm.h | 2 ++ > arch/arm64/kvm/handle_exit.c | 12 +++++++--- > 7 files changed, 65 insertions(+), 16 deletions(-) > > diff --git a/arch/arm/include/asm/kvm_psci.h b/arch/arm/include/asm/kvm_psci.h > index 9a83d98..992d7f1 100644 > --- a/arch/arm/include/asm/kvm_psci.h > +++ b/arch/arm/include/asm/kvm_psci.h > @@ -18,6 +18,6 @@ > #ifndef __ARM_KVM_PSCI_H__ > #define __ARM_KVM_PSCI_H__ > > -bool kvm_psci_call(struct kvm_vcpu *vcpu); > +int kvm_psci_call(struct kvm_vcpu *vcpu); > > #endif /* __ARM_KVM_PSCI_H__ */ > diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h > index c498b60..f4de20c 100644 > --- a/arch/arm/include/uapi/asm/kvm.h > +++ b/arch/arm/include/uapi/asm/kvm.h > @@ -172,6 +172,8 @@ struct kvm_arch_memory_slot { > #define KVM_PSCI_FN_CPU_OFF KVM_PSCI_FN(1) > #define KVM_PSCI_FN_CPU_ON KVM_PSCI_FN(2) > #define KVM_PSCI_FN_MIGRATE KVM_PSCI_FN(3) > +#define KVM_PSCI_FN_SYSTEM_OFF KVM_PSCI_FN(4) > +#define KVM_PSCI_FN_SYSTEM_RESET KVM_PSCI_FN(5) > > #define KVM_PSCI_RET_SUCCESS 0 > #define KVM_PSCI_RET_NI ((unsigned long)-1) > diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c > index a920790..c3f0e72 100644 > --- a/arch/arm/kvm/handle_exit.c > +++ b/arch/arm/kvm/handle_exit.c > @@ -40,14 +40,21 @@ static int handle_svc_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run) > > static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) > { > + int ret; > + > trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0), > kvm_vcpu_hvc_get_imm(vcpu)); > > - if (kvm_psci_call(vcpu)) > + ret = kvm_psci_call(vcpu); > + if (ret >= 0) > + return ret; > + else if (ret == -EINVAL) { > + kvm_inject_undefined(vcpu); > return 1; > + } > + > + return ret; Wouldn't ret = kvm_psci_call(vcpu); if (ret == -EINVAL) { kvm_inject_undefined(vcpu); return 1; } return ret; be simpler? also, minor nit, but I think according to the CodingStyle if you have single statements in if cases, but they are part of a larger if statement with alternative clauses that use curly-brackets to encapsulate multiple statements, then you should use curly braces around the single-line statement as well... > > - kvm_inject_undefined(vcpu); > - return 1; > } > > static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) > diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c > index 0881bf1..8e246d6 100644 > --- a/arch/arm/kvm/psci.c > +++ b/arch/arm/kvm/psci.c > @@ -84,18 +84,41 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) > return KVM_PSCI_RET_SUCCESS; > } > > +static inline void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type) > +{ > + memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event)); > + vcpu->run->system_event.type = type; > + vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT; > +} > + > +static void kvm_psci_system_off(struct kvm_vcpu *vcpu) > +{ > + kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN); > +} > + > +static void kvm_psci_system_reset(struct kvm_vcpu *vcpu) > +{ > + kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET); > +} > + > /** > * kvm_psci_call - handle PSCI call if r0 value is in range > * @vcpu: Pointer to the VCPU struct > * > * Handle PSCI calls from guests through traps from HVC instructions. > - * The calling convention is similar to SMC calls to the secure world where > - * the function number is placed in r0 and this function returns true if the > - * function number specified in r0 is withing the PSCI range, and false > - * otherwise. > + * The calling convention is similar to SMC calls to the secure world > + * where the function number is placed in r0 and function number the function number > + * specified in r0 is withing the PSCI range. this reads a little funny now. I think you can get rid of everything after the first mention of r0 (cut from "and function number...") since you explain that in the error codes below. > + * > + * This function returns: > 0 (success), 0 (success but exit to user > + * space), and < 0 (errors) you could use @return: instead of "This function returns", but I'm not sure if anyone actually cares. > + * > + * Errors: > + * -EINVAL: Unrecognized PSCI function > */ > -bool kvm_psci_call(struct kvm_vcpu *vcpu) > +int kvm_psci_call(struct kvm_vcpu *vcpu) > { > + int ret = 1; > unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); > unsigned long val; > > @@ -111,11 +134,20 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu) > case KVM_PSCI_FN_MIGRATE: > val = KVM_PSCI_RET_NI; > break; > - > + case KVM_PSCI_FN_SYSTEM_OFF: > + kvm_psci_system_off(vcpu); > + val = KVM_PSCI_RET_SUCCESS; > + ret = 0; > + break; > + case KVM_PSCI_FN_SYSTEM_RESET: > + kvm_psci_system_reset(vcpu); > + val = KVM_PSCI_RET_SUCCESS; > + ret = 0; > + break; > default: > - return false; > + return -EINVAL; > } > > *vcpu_reg(vcpu, 0) = val; > - return true; > + return ret; > } > diff --git a/arch/arm64/include/asm/kvm_psci.h b/arch/arm64/include/asm/kvm_psci.h > index e301a48..9bd0ee8 100644 > --- a/arch/arm64/include/asm/kvm_psci.h > +++ b/arch/arm64/include/asm/kvm_psci.h > @@ -18,6 +18,6 @@ > #ifndef __ARM64_KVM_PSCI_H__ > #define __ARM64_KVM_PSCI_H__ > > -bool kvm_psci_call(struct kvm_vcpu *vcpu); > +int kvm_psci_call(struct kvm_vcpu *vcpu); > > #endif /* __ARM64_KVM_PSCI_H__ */ > diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h > index d9f026b..f678902 100644 > --- a/arch/arm64/include/uapi/asm/kvm.h > +++ b/arch/arm64/include/uapi/asm/kvm.h > @@ -158,6 +158,8 @@ struct kvm_arch_memory_slot { > #define KVM_PSCI_FN_CPU_OFF KVM_PSCI_FN(1) > #define KVM_PSCI_FN_CPU_ON KVM_PSCI_FN(2) > #define KVM_PSCI_FN_MIGRATE KVM_PSCI_FN(3) > +#define KVM_PSCI_FN_SYSTEM_OFF KVM_PSCI_FN(4) > +#define KVM_PSCI_FN_SYSTEM_RESET KVM_PSCI_FN(5) > > #define KVM_PSCI_RET_SUCCESS 0 > #define KVM_PSCI_RET_NI ((unsigned long)-1) > diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c > index df84d7b..e382eb8 100644 > --- a/arch/arm64/kvm/handle_exit.c > +++ b/arch/arm64/kvm/handle_exit.c > @@ -30,11 +30,17 @@ typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *); > > static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) > { > - if (kvm_psci_call(vcpu)) > + int ret; > + > + ret = kvm_psci_call(vcpu); > + if (ret >= 0) > + return ret; > + else if (ret == -EINVAL) { > + kvm_inject_undefined(vcpu); > return 1; > + } > > - kvm_inject_undefined(vcpu); > - return 1; > + return ret; same as above. > } > > static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) > -- > 1.7.9.5 > Aside from the code formatting and commenting above, it looks pretty good to me. -Christoffer