From 1a2fb94e6a771ff94f4afa22497a4695187b820c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Feb 2018 17:56:08 +0000 Subject: arm/arm64: KVM: Consolidate the PSCI include files As we're about to update the PSCI support, and because I'm lazy, let's move the PSCI include file to include/kvm so that both ARM architectures can find it. Acked-by: Christoffer Dall Tested-by: Ard Biesheuvel Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas --- virt/kvm/arm/arm.c | 2 +- virt/kvm/arm/psci.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) (limited to 'virt') diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 15bf026eb182..af3e98fc377e 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -31,6 +31,7 @@ #include #include #include +#include #define CREATE_TRACE_POINTS #include "trace.h" @@ -46,7 +47,6 @@ #include #include #include -#include #include #ifdef REQUIRES_VIRT diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index f1e363bab5e8..b322e46fd142 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -21,9 +21,10 @@ #include #include -#include #include +#include + #include /* -- cgit v1.2.3 From d0a144f12a7ca8368933eae6583c096c363ec506 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Feb 2018 17:56:09 +0000 Subject: arm/arm64: KVM: Add PSCI_VERSION helper As we're about to trigger a PSCI version explosion, it doesn't hurt to introduce a PSCI_VERSION helper that is going to be used everywhere. Reviewed-by: Christoffer Dall Tested-by: Ard Biesheuvel Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas --- include/kvm/arm_psci.h | 6 ++++-- include/uapi/linux/psci.h | 3 +++ virt/kvm/arm/psci.c | 4 +--- 3 files changed, 8 insertions(+), 5 deletions(-) (limited to 'virt') diff --git a/include/kvm/arm_psci.h b/include/kvm/arm_psci.h index 2042bb909474..5659343580a3 100644 --- a/include/kvm/arm_psci.h +++ b/include/kvm/arm_psci.h @@ -18,8 +18,10 @@ #ifndef __KVM_ARM_PSCI_H__ #define __KVM_ARM_PSCI_H__ -#define KVM_ARM_PSCI_0_1 1 -#define KVM_ARM_PSCI_0_2 2 +#include + +#define KVM_ARM_PSCI_0_1 PSCI_VERSION(0, 1) +#define KVM_ARM_PSCI_0_2 PSCI_VERSION(0, 2) int kvm_psci_version(struct kvm_vcpu *vcpu); int kvm_psci_call(struct kvm_vcpu *vcpu); diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h index 760e52a9640f..b3bcabe380da 100644 --- a/include/uapi/linux/psci.h +++ b/include/uapi/linux/psci.h @@ -88,6 +88,9 @@ (((ver) & PSCI_VERSION_MAJOR_MASK) >> PSCI_VERSION_MAJOR_SHIFT) #define PSCI_VERSION_MINOR(ver) \ ((ver) & PSCI_VERSION_MINOR_MASK) +#define PSCI_VERSION(maj, min) \ + ((((maj) << PSCI_VERSION_MAJOR_SHIFT) & PSCI_VERSION_MAJOR_MASK) | \ + ((min) & PSCI_VERSION_MINOR_MASK)) /* PSCI features decoding (>=1.0) */ #define PSCI_1_0_FEATURES_CPU_SUSPEND_PF_SHIFT 1 diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index b322e46fd142..999f94d6bb98 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -25,8 +25,6 @@ #include -#include - /* * This is an implementation of the Power State Coordination Interface * as described in ARM document number ARM DEN 0022A. @@ -222,7 +220,7 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) * Bits[31:16] = Major Version = 0 * Bits[15:0] = Minor Version = 2 */ - val = 2; + val = KVM_ARM_PSCI_0_2; break; case PSCI_0_2_FN_CPU_SUSPEND: case PSCI_0_2_FN64_CPU_SUSPEND: -- cgit v1.2.3 From 84684fecd7ea381824a96634a027b7719587fb77 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Feb 2018 17:56:10 +0000 Subject: arm/arm64: KVM: Add smccc accessors to PSCI code Instead of open coding the accesses to the various registers, let's add explicit SMCCC accessors. Reviewed-by: Christoffer Dall Tested-by: Ard Biesheuvel Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas --- virt/kvm/arm/psci.c | 52 ++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 42 insertions(+), 10 deletions(-) (limited to 'virt') diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index 999f94d6bb98..c41553d35110 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -32,6 +32,38 @@ #define AFFINITY_MASK(level) ~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1) +static u32 smccc_get_function(struct kvm_vcpu *vcpu) +{ + return vcpu_get_reg(vcpu, 0); +} + +static unsigned long smccc_get_arg1(struct kvm_vcpu *vcpu) +{ + return vcpu_get_reg(vcpu, 1); +} + +static unsigned long smccc_get_arg2(struct kvm_vcpu *vcpu) +{ + return vcpu_get_reg(vcpu, 2); +} + +static unsigned long smccc_get_arg3(struct kvm_vcpu *vcpu) +{ + return vcpu_get_reg(vcpu, 3); +} + +static void smccc_set_retval(struct kvm_vcpu *vcpu, + unsigned long a0, + unsigned long a1, + unsigned long a2, + unsigned long a3) +{ + vcpu_set_reg(vcpu, 0, a0); + vcpu_set_reg(vcpu, 1, a1); + vcpu_set_reg(vcpu, 2, a2); + vcpu_set_reg(vcpu, 3, a3); +} + static unsigned long psci_affinity_mask(unsigned long affinity_level) { if (affinity_level <= 3) @@ -77,7 +109,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) unsigned long context_id; phys_addr_t target_pc; - cpu_id = vcpu_get_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK; + cpu_id = smccc_get_arg1(source_vcpu) & MPIDR_HWID_BITMASK; if (vcpu_mode_is_32bit(source_vcpu)) cpu_id &= ~((u32) 0); @@ -96,8 +128,8 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) return PSCI_RET_INVALID_PARAMS; } - target_pc = vcpu_get_reg(source_vcpu, 2); - context_id = vcpu_get_reg(source_vcpu, 3); + target_pc = smccc_get_arg2(source_vcpu); + context_id = smccc_get_arg3(source_vcpu); kvm_reset_vcpu(vcpu); @@ -116,7 +148,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) * NOTE: We always update r0 (or x0) because for PSCI v0.1 * the general puspose registers are undefined upon CPU_ON. */ - vcpu_set_reg(vcpu, 0, context_id); + smccc_set_retval(vcpu, context_id, 0, 0, 0); vcpu->arch.power_off = false; smp_mb(); /* Make sure the above is visible */ @@ -136,8 +168,8 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu) struct kvm *kvm = vcpu->kvm; struct kvm_vcpu *tmp; - target_affinity = vcpu_get_reg(vcpu, 1); - lowest_affinity_level = vcpu_get_reg(vcpu, 2); + target_affinity = smccc_get_arg1(vcpu); + lowest_affinity_level = smccc_get_arg2(vcpu); /* Determine target affinity mask */ target_affinity_mask = psci_affinity_mask(lowest_affinity_level); @@ -210,7 +242,7 @@ int kvm_psci_version(struct kvm_vcpu *vcpu) static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) { struct kvm *kvm = vcpu->kvm; - unsigned long psci_fn = vcpu_get_reg(vcpu, 0) & ~((u32) 0); + u32 psci_fn = smccc_get_function(vcpu); unsigned long val; int ret = 1; @@ -277,14 +309,14 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) break; } - vcpu_set_reg(vcpu, 0, val); + smccc_set_retval(vcpu, val, 0, 0, 0); return ret; } static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) { struct kvm *kvm = vcpu->kvm; - unsigned long psci_fn = vcpu_get_reg(vcpu, 0) & ~((u32) 0); + u32 psci_fn = smccc_get_function(vcpu); unsigned long val; switch (psci_fn) { @@ -302,7 +334,7 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) break; } - vcpu_set_reg(vcpu, 0, val); + smccc_set_retval(vcpu, val, 0, 0, 0); return 1; } -- cgit v1.2.3 From 58e0b2239a4d997094ba63986ef4de29ddc91d87 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Feb 2018 17:56:11 +0000 Subject: arm/arm64: KVM: Implement PSCI 1.0 support PSCI 1.0 can be trivially implemented by providing the FEATURES call on top of PSCI 0.2 and returning 1.0 as the PSCI version. We happily ignore everything else, as they are either optional or are clarifications that do not require any additional change. PSCI 1.0 is now the default until we decide to add a userspace selection API. Reviewed-by: Christoffer Dall Tested-by: Ard Biesheuvel Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas --- include/kvm/arm_psci.h | 3 +++ virt/kvm/arm/psci.c | 45 ++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 47 insertions(+), 1 deletion(-) (limited to 'virt') diff --git a/include/kvm/arm_psci.h b/include/kvm/arm_psci.h index 5659343580a3..32360432cff5 100644 --- a/include/kvm/arm_psci.h +++ b/include/kvm/arm_psci.h @@ -22,6 +22,9 @@ #define KVM_ARM_PSCI_0_1 PSCI_VERSION(0, 1) #define KVM_ARM_PSCI_0_2 PSCI_VERSION(0, 2) +#define KVM_ARM_PSCI_1_0 PSCI_VERSION(1, 0) + +#define KVM_ARM_PSCI_LATEST KVM_ARM_PSCI_1_0 int kvm_psci_version(struct kvm_vcpu *vcpu); int kvm_psci_call(struct kvm_vcpu *vcpu); diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index c41553d35110..3e7c63e15f04 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -234,7 +234,7 @@ static void kvm_psci_system_reset(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_LATEST; return KVM_ARM_PSCI_0_1; } @@ -313,6 +313,47 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) return ret; } +static int kvm_psci_1_0_call(struct kvm_vcpu *vcpu) +{ + u32 psci_fn = smccc_get_function(vcpu); + u32 feature; + unsigned long val; + int ret = 1; + + switch(psci_fn) { + case PSCI_0_2_FN_PSCI_VERSION: + val = KVM_ARM_PSCI_1_0; + break; + case PSCI_1_0_FN_PSCI_FEATURES: + feature = smccc_get_arg1(vcpu); + switch(feature) { + case PSCI_0_2_FN_PSCI_VERSION: + case PSCI_0_2_FN_CPU_SUSPEND: + case PSCI_0_2_FN64_CPU_SUSPEND: + case PSCI_0_2_FN_CPU_OFF: + case PSCI_0_2_FN_CPU_ON: + case PSCI_0_2_FN64_CPU_ON: + case PSCI_0_2_FN_AFFINITY_INFO: + case PSCI_0_2_FN64_AFFINITY_INFO: + case PSCI_0_2_FN_MIGRATE_INFO_TYPE: + case PSCI_0_2_FN_SYSTEM_OFF: + case PSCI_0_2_FN_SYSTEM_RESET: + case PSCI_1_0_FN_PSCI_FEATURES: + val = 0; + break; + default: + val = PSCI_RET_NOT_SUPPORTED; + break; + } + break; + default: + return kvm_psci_0_2_call(vcpu); + } + + smccc_set_retval(vcpu, val, 0, 0, 0); + return ret; +} + static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) { struct kvm *kvm = vcpu->kvm; @@ -355,6 +396,8 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) int kvm_psci_call(struct kvm_vcpu *vcpu) { switch (kvm_psci_version(vcpu)) { + case KVM_ARM_PSCI_1_0: + return kvm_psci_1_0_call(vcpu); case KVM_ARM_PSCI_0_2: return kvm_psci_0_2_call(vcpu); case KVM_ARM_PSCI_0_1: -- cgit v1.2.3 From 09e6be12effdb33bf7210c8867bbd213b66a499e Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Feb 2018 17:56:12 +0000 Subject: arm/arm64: KVM: Advertise SMCCC v1.1 The new SMC Calling Convention (v1.1) allows for a reduced overhead when calling into the firmware, and provides a new feature discovery mechanism. Make it visible to KVM guests. Tested-by: Ard Biesheuvel Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas --- arch/arm/kvm/handle_exit.c | 2 +- arch/arm64/kvm/handle_exit.c | 2 +- include/kvm/arm_psci.h | 2 +- include/linux/arm-smccc.h | 13 +++++++++++++ virt/kvm/arm/psci.c | 24 +++++++++++++++++++++++- 5 files changed, 39 insertions(+), 4 deletions(-) (limited to 'virt') diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c index 230ae4079108..910bd8dabb3c 100644 --- a/arch/arm/kvm/handle_exit.c +++ b/arch/arm/kvm/handle_exit.c @@ -36,7 +36,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) kvm_vcpu_hvc_get_imm(vcpu)); vcpu->stat.hvc_exit_stat++; - ret = kvm_psci_call(vcpu); + ret = kvm_hvc_call_handler(vcpu); if (ret < 0) { vcpu_set_reg(vcpu, 0, ~0UL); return 1; diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 588f910632a7..e5e741bfffe1 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -52,7 +52,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) kvm_vcpu_hvc_get_imm(vcpu)); vcpu->stat.hvc_exit_stat++; - ret = kvm_psci_call(vcpu); + ret = kvm_hvc_call_handler(vcpu); if (ret < 0) { vcpu_set_reg(vcpu, 0, ~0UL); return 1; diff --git a/include/kvm/arm_psci.h b/include/kvm/arm_psci.h index 32360432cff5..ed1dd8088f1c 100644 --- a/include/kvm/arm_psci.h +++ b/include/kvm/arm_psci.h @@ -27,6 +27,6 @@ #define KVM_ARM_PSCI_LATEST KVM_ARM_PSCI_1_0 int kvm_psci_version(struct kvm_vcpu *vcpu); -int kvm_psci_call(struct kvm_vcpu *vcpu); +int kvm_hvc_call_handler(struct kvm_vcpu *vcpu); #endif /* __KVM_ARM_PSCI_H__ */ diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h index 4c5bca38c653..dc68aa5a7261 100644 --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -60,6 +60,19 @@ #define ARM_SMCCC_QUIRK_NONE 0 #define ARM_SMCCC_QUIRK_QCOM_A6 1 /* Save/restore register a6 */ +#define ARM_SMCCC_VERSION_1_0 0x10000 +#define ARM_SMCCC_VERSION_1_1 0x10001 + +#define ARM_SMCCC_VERSION_FUNC_ID \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_32, \ + 0, 0) + +#define ARM_SMCCC_ARCH_FEATURES_FUNC_ID \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_32, \ + 0, 1) + #ifndef __ASSEMBLY__ #include diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index 3e7c63e15f04..46a98fee3ef5 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -15,6 +15,7 @@ * along with this program. If not, see . */ +#include #include #include #include @@ -339,6 +340,7 @@ static int kvm_psci_1_0_call(struct kvm_vcpu *vcpu) case PSCI_0_2_FN_SYSTEM_OFF: case PSCI_0_2_FN_SYSTEM_RESET: case PSCI_1_0_FN_PSCI_FEATURES: + case ARM_SMCCC_VERSION_FUNC_ID: val = 0; break; default: @@ -393,7 +395,7 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) * Errors: * -EINVAL: Unrecognized PSCI function */ -int kvm_psci_call(struct kvm_vcpu *vcpu) +static int kvm_psci_call(struct kvm_vcpu *vcpu) { switch (kvm_psci_version(vcpu)) { case KVM_ARM_PSCI_1_0: @@ -406,3 +408,23 @@ int kvm_psci_call(struct kvm_vcpu *vcpu) return -EINVAL; }; } + +int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) +{ + u32 func_id = smccc_get_function(vcpu); + u32 val = PSCI_RET_NOT_SUPPORTED; + + switch (func_id) { + case ARM_SMCCC_VERSION_FUNC_ID: + val = ARM_SMCCC_VERSION_1_1; + break; + case ARM_SMCCC_ARCH_FEATURES_FUNC_ID: + /* Nothing supported yet */ + break; + default: + return kvm_psci_call(vcpu); + } + + smccc_set_retval(vcpu, val, 0, 0, 0); + return 1; +} -- cgit v1.2.3 From a4097b351118e821841941a79ec77d3ce3f1c5d9 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Feb 2018 17:56:13 +0000 Subject: arm/arm64: KVM: Turn kvm_psci_version into a static inline We're about to need kvm_psci_version in HYP too. So let's turn it into a static inline, and pass the kvm structure as a second parameter (so that HYP can do a kern_hyp_va on it). Tested-by: Ard Biesheuvel Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas --- arch/arm64/kvm/hyp/switch.c | 20 ++++++++++++-------- include/kvm/arm_psci.h | 21 ++++++++++++++++++++- virt/kvm/arm/psci.c | 12 ++---------- 3 files changed, 34 insertions(+), 19 deletions(-) (limited to 'virt') diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 036e1f3d77a6..408c04d789a5 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -19,6 +19,8 @@ #include #include +#include + #include #include #include @@ -350,14 +352,16 @@ again: if (exit_code == ARM_EXCEPTION_TRAP && (kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_HVC64 || - kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_HVC32) && - vcpu_get_reg(vcpu, 0) == PSCI_0_2_FN_PSCI_VERSION) { - u64 val = PSCI_RET_NOT_SUPPORTED; - if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) - val = 2; - - vcpu_set_reg(vcpu, 0, val); - goto again; + kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_HVC32)) { + u32 val = vcpu_get_reg(vcpu, 0); + + if (val == PSCI_0_2_FN_PSCI_VERSION) { + val = kvm_psci_version(vcpu, kern_hyp_va(vcpu->kvm)); + if (unlikely(val == KVM_ARM_PSCI_0_1)) + val = PSCI_RET_NOT_SUPPORTED; + vcpu_set_reg(vcpu, 0, val); + goto again; + } } if (static_branch_unlikely(&vgic_v2_cpuif_trap) && diff --git a/include/kvm/arm_psci.h b/include/kvm/arm_psci.h index ed1dd8088f1c..e518e4e3dfb5 100644 --- a/include/kvm/arm_psci.h +++ b/include/kvm/arm_psci.h @@ -18,6 +18,7 @@ #ifndef __KVM_ARM_PSCI_H__ #define __KVM_ARM_PSCI_H__ +#include #include #define KVM_ARM_PSCI_0_1 PSCI_VERSION(0, 1) @@ -26,7 +27,25 @@ #define KVM_ARM_PSCI_LATEST KVM_ARM_PSCI_1_0 -int kvm_psci_version(struct kvm_vcpu *vcpu); +/* + * We need the KVM pointer independently from the vcpu as we can call + * this from HYP, and need to apply kern_hyp_va on it... + */ +static inline int kvm_psci_version(struct kvm_vcpu *vcpu, struct kvm *kvm) +{ + /* + * Our PSCI implementation stays the same across versions from + * v0.2 onward, only adding the few mandatory functions (such + * as FEATURES with 1.0) that are required by newer + * revisions. It is thus safe to return the latest. + */ + if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) + return KVM_ARM_PSCI_LATEST; + + return KVM_ARM_PSCI_0_1; +} + + int kvm_hvc_call_handler(struct kvm_vcpu *vcpu); #endif /* __KVM_ARM_PSCI_H__ */ diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index 46a98fee3ef5..e105c1153794 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -123,7 +123,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) if (!vcpu) return PSCI_RET_INVALID_PARAMS; if (!vcpu->arch.power_off) { - if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1) + if (kvm_psci_version(source_vcpu, kvm) != KVM_ARM_PSCI_0_1) return PSCI_RET_ALREADY_ON; else return PSCI_RET_INVALID_PARAMS; @@ -232,14 +232,6 @@ 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)) - return KVM_ARM_PSCI_LATEST; - - return KVM_ARM_PSCI_0_1; -} - static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) { struct kvm *kvm = vcpu->kvm; @@ -397,7 +389,7 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) */ static int kvm_psci_call(struct kvm_vcpu *vcpu) { - switch (kvm_psci_version(vcpu)) { + switch (kvm_psci_version(vcpu, vcpu->kvm)) { case KVM_ARM_PSCI_1_0: return kvm_psci_1_0_call(vcpu); case KVM_ARM_PSCI_0_2: -- cgit v1.2.3 From 6167ec5c9145cdf493722dfd80a5d48bafc4a18a Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Feb 2018 17:56:14 +0000 Subject: arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support A new feature of SMCCC 1.1 is that it offers firmware-based CPU workarounds. In particular, SMCCC_ARCH_WORKAROUND_1 provides BP hardening for CVE-2017-5715. If the host has some mitigation for this issue, report that we deal with it using SMCCC_ARCH_WORKAROUND_1, as we apply the host workaround on every guest exit. Tested-by: Ard Biesheuvel Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas --- arch/arm/include/asm/kvm_host.h | 7 +++++++ arch/arm64/include/asm/kvm_host.h | 6 ++++++ include/linux/arm-smccc.h | 5 +++++ virt/kvm/arm/psci.c | 9 ++++++++- 4 files changed, 26 insertions(+), 1 deletion(-) (limited to 'virt') diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index acbf9ec7b396..ef54013b5b9f 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -306,4 +306,11 @@ static inline void kvm_fpsimd_flush_cpu_state(void) {} static inline void kvm_arm_vhe_guest_enter(void) {} static inline void kvm_arm_vhe_guest_exit(void) {} + +static inline bool kvm_arm_harden_branch_predictor(void) +{ + /* No way to detect it yet, pretend it is not there. */ + return false; +} + #endif /* __ARM_KVM_HOST_H__ */ diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 4485ae8e98de..a73f63aca68e 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -415,4 +415,10 @@ static inline void kvm_arm_vhe_guest_exit(void) { local_daif_restore(DAIF_PROCCTX_NOIRQ); } + +static inline bool kvm_arm_harden_branch_predictor(void) +{ + return cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR); +} + #endif /* __ARM64_KVM_HOST_H__ */ diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h index dc68aa5a7261..e1ef944ef1da 100644 --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -73,6 +73,11 @@ ARM_SMCCC_SMC_32, \ 0, 1) +#define ARM_SMCCC_ARCH_WORKAROUND_1 \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_32, \ + 0, 0x8000) + #ifndef __ASSEMBLY__ #include diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index e105c1153794..6919352cbf15 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -405,13 +405,20 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) { u32 func_id = smccc_get_function(vcpu); u32 val = PSCI_RET_NOT_SUPPORTED; + u32 feature; switch (func_id) { case ARM_SMCCC_VERSION_FUNC_ID: val = ARM_SMCCC_VERSION_1_1; break; case ARM_SMCCC_ARCH_FEATURES_FUNC_ID: - /* Nothing supported yet */ + feature = smccc_get_arg1(vcpu); + switch(feature) { + case ARM_SMCCC_ARCH_WORKAROUND_1: + if (kvm_arm_harden_branch_predictor()) + val = 0; + break; + } break; default: return kvm_psci_call(vcpu); -- cgit v1.2.3