From 7d0f84aae9e231930985eaff63ac91b61aaa15d6 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Tue, 29 Apr 2014 11:24:16 +0530 Subject: ARM/ARM64: KVM: Add base for PSCI v0.2 emulation Currently, the in-kernel PSCI emulation provides PSCI v0.1 interface to VCPUs. This patch extends current in-kernel PSCI emulation to provide PSCI v0.2 interface to VCPUs. By default, ARM/ARM64 KVM will always provide PSCI v0.1 interface for keeping the ABI backward-compatible. To select PSCI v0.2 interface for VCPUs, the user space (i.e. QEMU or KVMTOOL) will have to set KVM_ARM_VCPU_PSCI_0_2 feature when doing VCPU init using KVM_ARM_VCPU_INIT ioctl. Signed-off-by: Anup Patel Signed-off-by: Pranavkumar Sawargaonkar Acked-by: Christoffer Dall Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/kvm/psci.c | 93 ++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 77 insertions(+), 16 deletions(-) (limited to 'arch/arm/kvm') diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 448f60e8d23c..8c42596cdbdf 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -59,7 +59,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) * turned off. */ if (!vcpu || !vcpu->arch.pause) - return KVM_PSCI_RET_INVAL; + return PSCI_RET_INVALID_PARAMS; target_pc = *vcpu_reg(source_vcpu, 2); @@ -82,20 +82,60 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) wq = kvm_arch_vcpu_wq(vcpu); wake_up_interruptible(wq); - return KVM_PSCI_RET_SUCCESS; + return PSCI_RET_SUCCESS; } -/** - * 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. - */ -bool kvm_psci_call(struct kvm_vcpu *vcpu) +int kvm_psci_version(struct kvm_vcpu *vcpu) +{ + if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) + return KVM_ARM_PSCI_0_2; + + return KVM_ARM_PSCI_0_1; +} + +static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu) +{ + unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); + unsigned long val; + + switch (psci_fn) { + case PSCI_0_2_FN_PSCI_VERSION: + /* + * Bits[31:16] = Major Version = 0 + * Bits[15:0] = Minor Version = 2 + */ + val = 2; + break; + case PSCI_0_2_FN_CPU_OFF: + kvm_psci_vcpu_off(vcpu); + val = PSCI_RET_SUCCESS; + break; + case PSCI_0_2_FN_CPU_ON: + case PSCI_0_2_FN64_CPU_ON: + val = kvm_psci_vcpu_on(vcpu); + break; + case PSCI_0_2_FN_CPU_SUSPEND: + case PSCI_0_2_FN_AFFINITY_INFO: + case PSCI_0_2_FN_MIGRATE: + case PSCI_0_2_FN_MIGRATE_INFO_TYPE: + case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU: + case PSCI_0_2_FN_SYSTEM_OFF: + case PSCI_0_2_FN_SYSTEM_RESET: + case PSCI_0_2_FN64_CPU_SUSPEND: + case PSCI_0_2_FN64_AFFINITY_INFO: + case PSCI_0_2_FN64_MIGRATE: + case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU: + val = PSCI_RET_NOT_SUPPORTED; + break; + default: + return false; + } + + *vcpu_reg(vcpu, 0) = val; + return true; +} + +static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu) { unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); unsigned long val; @@ -103,16 +143,15 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu) switch (psci_fn) { case KVM_PSCI_FN_CPU_OFF: kvm_psci_vcpu_off(vcpu); - val = KVM_PSCI_RET_SUCCESS; + val = PSCI_RET_SUCCESS; break; case KVM_PSCI_FN_CPU_ON: val = kvm_psci_vcpu_on(vcpu); break; case KVM_PSCI_FN_CPU_SUSPEND: case KVM_PSCI_FN_MIGRATE: - val = KVM_PSCI_RET_NI; + val = PSCI_RET_NOT_SUPPORTED; break; - default: return false; } @@ -120,3 +159,25 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu) *vcpu_reg(vcpu, 0) = val; return true; } + +/** + * 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. + */ +bool kvm_psci_call(struct kvm_vcpu *vcpu) +{ + switch (kvm_psci_version(vcpu)) { + case KVM_ARM_PSCI_0_2: + return kvm_psci_0_2_call(vcpu); + case KVM_ARM_PSCI_0_1: + return kvm_psci_0_1_call(vcpu); + default: + return false; + }; +} -- cgit v1.2.1 From e8e7fcc5e2710b31ef842ee799db99c07986c364 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Tue, 29 Apr 2014 11:24:18 +0530 Subject: ARM/ARM64: KVM: Make kvm_psci_call() return convention more flexible Currently, the kvm_psci_call() returns 'true' or 'false' based on whether the PSCI function call was handled successfully or not. This does not help us emulate system-level PSCI functions where the actual emulation work will be done by user space (QEMU or KVMTOOL). Examples of such system-level PSCI functions are: PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET. This patch updates kvm_psci_call() to return three types of values: 1) > 0 (success) 2) = 0 (success but exit to user space) 3) < 0 (errors) Signed-off-by: Anup Patel Signed-off-by: Pranavkumar Sawargaonkar Reviewed-by: Christoffer Dall Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/kvm/handle_exit.c | 10 +++++++--- arch/arm/kvm/psci.c | 28 ++++++++++++++++------------ 2 files changed, 23 insertions(+), 15 deletions(-) (limited to 'arch/arm/kvm') diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c index 0de91fc6de0f..4c979d466cc1 100644 --- a/arch/arm/kvm/handle_exit.c +++ b/arch/arm/kvm/handle_exit.c @@ -38,14 +38,18 @@ 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) { + kvm_inject_undefined(vcpu); return 1; + } - kvm_inject_undefined(vcpu); - return 1; + return ret; } 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 8c42596cdbdf..14e6fa6c8e35 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -93,7 +93,7 @@ int kvm_psci_version(struct kvm_vcpu *vcpu) return KVM_ARM_PSCI_0_1; } -static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu) +static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) { unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); unsigned long val; @@ -128,14 +128,14 @@ static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu) val = PSCI_RET_NOT_SUPPORTED; break; default: - return false; + return -EINVAL; } *vcpu_reg(vcpu, 0) = val; - return true; + return 1; } -static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu) +static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) { unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); unsigned long val; @@ -153,11 +153,11 @@ static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu) val = PSCI_RET_NOT_SUPPORTED; break; default: - return false; + return -EINVAL; } *vcpu_reg(vcpu, 0) = val; - return true; + return 1; } /** @@ -165,12 +165,16 @@ static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu) * @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. + * + * This function returns: > 0 (success), 0 (success but exit to user + * space), and < 0 (errors) + * + * Errors: + * -EINVAL: Unrecognized PSCI function */ -bool kvm_psci_call(struct kvm_vcpu *vcpu) +int kvm_psci_call(struct kvm_vcpu *vcpu) { switch (kvm_psci_version(vcpu)) { case KVM_ARM_PSCI_0_2: @@ -178,6 +182,6 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu) case KVM_ARM_PSCI_0_1: return kvm_psci_0_1_call(vcpu); default: - return false; + return -EINVAL; }; } -- cgit v1.2.1 From 4b1238269ed340d59ef829fd9c30a39cfb2923a8 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Tue, 29 Apr 2014 11:24:20 +0530 Subject: ARM/ARM64: KVM: Emulate PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET The PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET functions are system-level functions hence cannot be fully emulated by in-kernel PSCI emulation code. To tackle this, we forward PSCI v0.2 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 Reviewed-by: Christoffer Dall Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/kvm/psci.c | 46 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 43 insertions(+), 3 deletions(-) (limited to 'arch/arm/kvm') diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 14e6fa6c8e35..59362131b79f 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -85,6 +85,23 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) return PSCI_RET_SUCCESS; } +static 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); +} + int kvm_psci_version(struct kvm_vcpu *vcpu) { if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) @@ -95,6 +112,7 @@ int kvm_psci_version(struct kvm_vcpu *vcpu) static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) { + int ret = 1; unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); unsigned long val; @@ -114,13 +132,35 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) case PSCI_0_2_FN64_CPU_ON: val = kvm_psci_vcpu_on(vcpu); break; + case PSCI_0_2_FN_SYSTEM_OFF: + kvm_psci_system_off(vcpu); + /* + * We should'nt be going back to guest VCPU after + * receiving SYSTEM_OFF request. + * + * If user space accidently/deliberately resumes + * guest VCPU after SYSTEM_OFF request then guest + * VCPU should see internal failure from PSCI return + * value. To achieve this, we preload r0 (or x0) with + * PSCI return value INTERNAL_FAILURE. + */ + val = PSCI_RET_INTERNAL_FAILURE; + ret = 0; + break; + case PSCI_0_2_FN_SYSTEM_RESET: + kvm_psci_system_reset(vcpu); + /* + * Same reason as SYSTEM_OFF for preloading r0 (or x0) + * with PSCI return value INTERNAL_FAILURE. + */ + val = PSCI_RET_INTERNAL_FAILURE; + ret = 0; + break; case PSCI_0_2_FN_CPU_SUSPEND: case PSCI_0_2_FN_AFFINITY_INFO: case PSCI_0_2_FN_MIGRATE: case PSCI_0_2_FN_MIGRATE_INFO_TYPE: case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU: - case PSCI_0_2_FN_SYSTEM_OFF: - case PSCI_0_2_FN_SYSTEM_RESET: case PSCI_0_2_FN64_CPU_SUSPEND: case PSCI_0_2_FN64_AFFINITY_INFO: case PSCI_0_2_FN64_MIGRATE: @@ -132,7 +172,7 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) } *vcpu_reg(vcpu, 0) = val; - return 1; + return ret; } static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) -- cgit v1.2.1 From e6bc13c8a70eabc6a39098ccedf6129c734e3db3 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Tue, 29 Apr 2014 11:24:21 +0530 Subject: ARM/ARM64: KVM: Emulate PSCI v0.2 AFFINITY_INFO This patch adds emulation of PSCI v0.2 AFFINITY_INFO function call for KVM ARM/ARM64. This is a VCPU-level function call which will be used to determine current state of given affinity level. Signed-off-by: Anup Patel Signed-off-by: Pranavkumar Sawargaonkar Reviewed-by: Christoffer Dall Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/kvm/psci.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 50 insertions(+), 2 deletions(-) (limited to 'arch/arm/kvm') diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 59362131b79f..3b6a0cf25c7d 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -27,6 +27,16 @@ * as described in ARM document number ARM DEN 0022A. */ +#define AFFINITY_MASK(level) ~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1) + +static unsigned long psci_affinity_mask(unsigned long affinity_level) +{ + if (affinity_level <= 3) + return MPIDR_HWID_BITMASK & AFFINITY_MASK(affinity_level); + + return 0; +} + static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) { vcpu->arch.pause = true; @@ -85,6 +95,42 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) return PSCI_RET_SUCCESS; } +static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu) +{ + int i; + unsigned long mpidr; + unsigned long target_affinity; + unsigned long target_affinity_mask; + unsigned long lowest_affinity_level; + struct kvm *kvm = vcpu->kvm; + struct kvm_vcpu *tmp; + + target_affinity = *vcpu_reg(vcpu, 1); + lowest_affinity_level = *vcpu_reg(vcpu, 2); + + /* Determine target affinity mask */ + target_affinity_mask = psci_affinity_mask(lowest_affinity_level); + if (!target_affinity_mask) + return PSCI_RET_INVALID_PARAMS; + + /* Ignore other bits of target affinity */ + target_affinity &= target_affinity_mask; + + /* + * If one or more VCPU matching target affinity are running + * then ON else OFF + */ + kvm_for_each_vcpu(i, tmp, kvm) { + mpidr = kvm_vcpu_get_mpidr(tmp); + if (((mpidr & target_affinity_mask) == target_affinity) && + !tmp->arch.pause) { + return PSCI_0_2_AFFINITY_LEVEL_ON; + } + } + + return PSCI_0_2_AFFINITY_LEVEL_OFF; +} + static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type) { memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event)); @@ -132,6 +178,10 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) case PSCI_0_2_FN64_CPU_ON: val = kvm_psci_vcpu_on(vcpu); break; + case PSCI_0_2_FN_AFFINITY_INFO: + case PSCI_0_2_FN64_AFFINITY_INFO: + val = kvm_psci_vcpu_affinity_info(vcpu); + break; case PSCI_0_2_FN_SYSTEM_OFF: kvm_psci_system_off(vcpu); /* @@ -157,12 +207,10 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) ret = 0; break; case PSCI_0_2_FN_CPU_SUSPEND: - case PSCI_0_2_FN_AFFINITY_INFO: case PSCI_0_2_FN_MIGRATE: case PSCI_0_2_FN_MIGRATE_INFO_TYPE: case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU: case PSCI_0_2_FN64_CPU_SUSPEND: - case PSCI_0_2_FN64_AFFINITY_INFO: case PSCI_0_2_FN64_MIGRATE: case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU: val = PSCI_RET_NOT_SUPPORTED; -- cgit v1.2.1 From bab0b43012a8ad64877fa46134370a7f5c6ce861 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Tue, 29 Apr 2014 11:24:22 +0530 Subject: ARM/ARM64: KVM: Emulate PSCI v0.2 MIGRATE_INFO_TYPE and related functions This patch adds emulation of PSCI v0.2 MIGRATE, MIGRATE_INFO_TYPE, and MIGRATE_INFO_UP_CPU function calls for KVM ARM/ARM64. KVM ARM/ARM64 being a hypervisor (and not a Trusted OS), we cannot provide this functions hence we emulate these functions in following way: 1. MIGRATE - Returns "Not Supported" 2. MIGRATE_INFO_TYPE - Return 2 i.e. Trusted OS is not present 3. MIGRATE_INFO_UP_CPU - Returns "Not Supported" Signed-off-by: Anup Patel Signed-off-by: Pranavkumar Sawargaonkar Reviewed-by: Christoffer Dall Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/kvm/psci.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) (limited to 'arch/arm/kvm') diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 3b6a0cf25c7d..cce901a510fa 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -182,6 +182,22 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) case PSCI_0_2_FN64_AFFINITY_INFO: val = kvm_psci_vcpu_affinity_info(vcpu); break; + case PSCI_0_2_FN_MIGRATE: + case PSCI_0_2_FN64_MIGRATE: + val = PSCI_RET_NOT_SUPPORTED; + break; + case PSCI_0_2_FN_MIGRATE_INFO_TYPE: + /* + * Trusted OS is MP hence does not require migration + * or + * Trusted OS is not present + */ + val = PSCI_0_2_TOS_MP; + break; + case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU: + case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU: + val = PSCI_RET_NOT_SUPPORTED; + break; case PSCI_0_2_FN_SYSTEM_OFF: kvm_psci_system_off(vcpu); /* @@ -207,12 +223,7 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) ret = 0; break; case PSCI_0_2_FN_CPU_SUSPEND: - case PSCI_0_2_FN_MIGRATE: - case PSCI_0_2_FN_MIGRATE_INFO_TYPE: - case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU: case PSCI_0_2_FN64_CPU_SUSPEND: - case PSCI_0_2_FN64_MIGRATE: - case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU: val = PSCI_RET_NOT_SUPPORTED; break; default: -- cgit v1.2.1 From aa8aeefe5e567637bbec7d7a3031cc057e3af303 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Tue, 29 Apr 2014 11:24:23 +0530 Subject: ARM/ARM64: KVM: Fix CPU_ON emulation for PSCI v0.2 As-per PSCI v0.2, the source CPU provides physical address of "entry point" and "context id" for starting a target CPU. Also, if target CPU is already running then we should return ALREADY_ON. Current emulation of CPU_ON function does not consider physical address of "context id" and returns INVALID_PARAMETERS if target CPU is already running. This patch updates kvm_psci_vcpu_on() such that it works for both PSCI v0.1 and PSCI v0.2. Signed-off-by: Anup Patel Signed-off-by: Pranavkumar Sawargaonkar Reviewed-by: Christoffer Dall Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/kvm/psci.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'arch/arm/kvm') diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index cce901a510fa..1067579c7336 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -48,6 +48,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) struct kvm_vcpu *vcpu = NULL, *tmp; wait_queue_head_t *wq; unsigned long cpu_id; + unsigned long context_id; unsigned long mpidr; phys_addr_t target_pc; int i; @@ -68,10 +69,17 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) * Make sure the caller requested a valid CPU and that the CPU is * turned off. */ - if (!vcpu || !vcpu->arch.pause) + if (!vcpu) return PSCI_RET_INVALID_PARAMS; + if (!vcpu->arch.pause) { + if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1) + return PSCI_RET_ALREADY_ON; + else + return PSCI_RET_INVALID_PARAMS; + } target_pc = *vcpu_reg(source_vcpu, 2); + context_id = *vcpu_reg(source_vcpu, 3); kvm_reset_vcpu(vcpu); @@ -86,6 +94,11 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) kvm_vcpu_set_be(vcpu); *vcpu_pc(vcpu) = target_pc; + /* + * NOTE: We always update r0 (or x0) because for PSCI v0.1 + * the general puspose registers are undefined upon CPU_ON. + */ + *vcpu_reg(vcpu, 0) = context_id; vcpu->arch.pause = false; smp_mb(); /* Make sure the above is visible */ -- cgit v1.2.1 From b376d02b53b87f8684f91f13ba4ee43331850fcd Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Tue, 29 Apr 2014 11:24:24 +0530 Subject: ARM/ARM64: KVM: Emulate PSCI v0.2 CPU_SUSPEND This patch adds emulation of PSCI v0.2 CPU_SUSPEND function call for KVM ARM/ARM64. This is a CPU-level function call which can suspend current CPU or current CPU cluster. We don't have VCPU clusters in KVM so we only suspend the current VCPU. The CPU_SUSPEND emulation is not tested much because currently there is no CPUIDLE driver in Linux kernel that uses PSCI CPU_SUSPEND. The PSCI CPU_SUSPEND implementation in ARM64 kernel was tested using a Simple CPUIDLE driver which is not published due to unstable DT-bindings for PSCI. (For more info, http://lwn.net/Articles/574950/) For simplicity, we implement CPU_SUSPEND emulation similar to WFI (Wait-for-interrupt) emulation and we also treat power-down request to be same as stand-by request. This is consistent with section 5.4.1 and section 5.4.2 of PSCI v0.2 specification. Signed-off-by: Anup Patel Signed-off-by: Pranavkumar Sawargaonkar Acked-by: Christoffer Dall Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/kvm/psci.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) (limited to 'arch/arm/kvm') diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 1067579c7336..09cf37737ee2 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -37,6 +37,26 @@ static unsigned long psci_affinity_mask(unsigned long affinity_level) return 0; } +static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu) +{ + /* + * NOTE: For simplicity, we make VCPU suspend emulation to be + * same-as WFI (Wait-for-interrupt) emulation. + * + * This means for KVM the wakeup events are interrupts and + * this is consistent with intended use of StateID as described + * in section 5.4.1 of PSCI v0.2 specification (ARM DEN 0022A). + * + * Further, we also treat power-down request to be same as + * stand-by request as-per section 5.4.2 clause 3 of PSCI v0.2 + * specification (ARM DEN 0022A). This means all suspend states + * for KVM will preserve the register state. + */ + kvm_vcpu_block(vcpu); + + return PSCI_RET_SUCCESS; +} + static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) { vcpu->arch.pause = true; @@ -183,6 +203,10 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) */ val = 2; break; + case PSCI_0_2_FN_CPU_SUSPEND: + case PSCI_0_2_FN64_CPU_SUSPEND: + val = kvm_psci_vcpu_suspend(vcpu); + break; case PSCI_0_2_FN_CPU_OFF: kvm_psci_vcpu_off(vcpu); val = PSCI_RET_SUCCESS; @@ -235,10 +259,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) val = PSCI_RET_INTERNAL_FAILURE; ret = 0; break; - case PSCI_0_2_FN_CPU_SUSPEND: - case PSCI_0_2_FN64_CPU_SUSPEND: - val = PSCI_RET_NOT_SUPPORTED; - break; default: return -EINVAL; } -- cgit v1.2.1 From 4447a208f7fc2e2dff8c6a8df2a1fd6dd72fb3e2 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Tue, 29 Apr 2014 11:24:25 +0530 Subject: ARM/ARM64: KVM: Advertise KVM_CAP_ARM_PSCI_0_2 to user space We have PSCI v0.2 emulation available in KVM ARM/ARM64 hence advertise this to user space (i.e. QEMU or KVMTOOL) via KVM_CHECK_EXTENSION ioctl. Signed-off-by: Anup Patel Signed-off-by: Pranavkumar Sawargaonkar Acked-by: Christoffer Dall Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/kvm/arm.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm/kvm') diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index f0e50a0f3a65..3c82b37c0f9e 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -197,6 +197,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_DESTROY_MEMORY_REGION_WORKS: case KVM_CAP_ONE_REG: case KVM_CAP_ARM_PSCI: + case KVM_CAP_ARM_PSCI_0_2: r = 1; break; case KVM_CAP_COALESCED_MMIO: -- cgit v1.2.1