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From foo@baz Tue Mar 8 08:47:19 PM CET 2022 |
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From: James Morse <james.morse@arm.com> |
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Date: Fri, 10 Dec 2021 11:16:18 +0000 |
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Subject: KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated |
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|
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From: James Morse <james.morse@arm.com> |
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|
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commit a5905d6af492ee6a4a2205f0d550b3f931b03d03 upstream. |
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|
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KVM allows the guest to discover whether the ARCH_WORKAROUND SMCCC are |
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implemented, and to preserve that state during migration through its |
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firmware register interface. |
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|
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Add the necessary boiler plate for SMCCC_ARCH_WORKAROUND_3. |
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|
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Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> |
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Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> |
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Signed-off-by: James Morse <james.morse@arm.com> |
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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--- |
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arch/arm64/include/uapi/asm/kvm.h | 5 +++++ |
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arch/arm64/kvm/hypercalls.c | 12 ++++++++++++ |
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arch/arm64/kvm/psci.c | 18 +++++++++++++++++- |
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3 files changed, 34 insertions(+), 1 deletion(-) |
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|
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--- a/arch/arm64/include/uapi/asm/kvm.h |
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+++ b/arch/arm64/include/uapi/asm/kvm.h |
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@@ -281,6 +281,11 @@ struct kvm_arm_copy_mte_tags { |
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#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED 3 |
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#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED (1U << 4) |
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|
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+#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3 KVM_REG_ARM_FW_REG(3) |
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+#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL 0 |
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+#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_AVAIL 1 |
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+#define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_REQUIRED 2 |
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+ |
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/* SVE registers */ |
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#define KVM_REG_ARM64_SVE (0x15 << KVM_REG_ARM_COPROC_SHIFT) |
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|
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--- a/arch/arm64/kvm/hypercalls.c |
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+++ b/arch/arm64/kvm/hypercalls.c |
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@@ -107,6 +107,18 @@ int kvm_hvc_call_handler(struct kvm_vcpu |
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break; |
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} |
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break; |
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+ case ARM_SMCCC_ARCH_WORKAROUND_3: |
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+ switch (arm64_get_spectre_bhb_state()) { |
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+ case SPECTRE_VULNERABLE: |
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+ break; |
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+ case SPECTRE_MITIGATED: |
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+ val[0] = SMCCC_RET_SUCCESS; |
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+ break; |
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+ case SPECTRE_UNAFFECTED: |
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+ val[0] = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED; |
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+ break; |
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+ } |
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+ break; |
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case ARM_SMCCC_HV_PV_TIME_FEATURES: |
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val[0] = SMCCC_RET_SUCCESS; |
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break; |
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--- a/arch/arm64/kvm/psci.c |
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+++ b/arch/arm64/kvm/psci.c |
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@@ -406,7 +406,7 @@ int kvm_psci_call(struct kvm_vcpu *vcpu) |
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|
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int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu) |
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{ |
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- return 3; /* PSCI version and two workaround registers */ |
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+ return 4; /* PSCI version and three workaround registers */ |
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} |
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|
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int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices) |
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@@ -420,6 +420,9 @@ int kvm_arm_copy_fw_reg_indices(struct k |
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if (put_user(KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2, uindices++)) |
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return -EFAULT; |
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|
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+ if (put_user(KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3, uindices++)) |
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+ return -EFAULT; |
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+ |
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return 0; |
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} |
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|
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@@ -459,6 +462,17 @@ static int get_kernel_wa_level(u64 regid |
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case SPECTRE_VULNERABLE: |
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return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL; |
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} |
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+ break; |
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+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3: |
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+ switch (arm64_get_spectre_bhb_state()) { |
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+ case SPECTRE_VULNERABLE: |
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+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL; |
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+ case SPECTRE_MITIGATED: |
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+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_AVAIL; |
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+ case SPECTRE_UNAFFECTED: |
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+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_REQUIRED; |
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+ } |
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+ return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL; |
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} |
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|
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return -EINVAL; |
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@@ -475,6 +489,7 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu * |
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break; |
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case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1: |
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case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2: |
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+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3: |
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val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK; |
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break; |
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default: |
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@@ -520,6 +535,7 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu * |
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} |
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|
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case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1: |
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+ case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3: |
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if (val & ~KVM_REG_FEATURE_LEVEL_MASK) |
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return -EINVAL; |
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