38c26bdb3c
commit a5905d6af492ee6a4a2205f0d550b3f931b03d03 upstream. KVM allows the guest to discover whether the ARCH_WORKAROUND SMCCC are implemented, and to preserve that state during migration through its firmware register interface. Add the necessary boiler plate for SMCCC_ARCH_WORKAROUND_3. Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
93 lines
2.1 KiB
C
93 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2019 Arm Ltd.
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#include <linux/arm-smccc.h>
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#include <linux/kvm_host.h>
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#include <asm/kvm_emulate.h>
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#include <kvm/arm_hypercalls.h>
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#include <kvm/arm_psci.h>
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int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
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{
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u32 func_id = smccc_get_function(vcpu);
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long val = SMCCC_RET_NOT_SUPPORTED;
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u32 feature;
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gpa_t gpa;
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switch (func_id) {
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case ARM_SMCCC_VERSION_FUNC_ID:
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val = ARM_SMCCC_VERSION_1_1;
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break;
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case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:
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feature = smccc_get_arg1(vcpu);
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switch (feature) {
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case ARM_SMCCC_ARCH_WORKAROUND_1:
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switch (arm64_get_spectre_v2_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 = SMCCC_RET_SUCCESS;
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break;
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case SPECTRE_UNAFFECTED:
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val = 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_ARCH_WORKAROUND_2:
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switch (arm64_get_spectre_v4_state()) {
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case SPECTRE_VULNERABLE:
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break;
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case SPECTRE_MITIGATED:
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/*
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* SSBS everywhere: Indicate no firmware
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* support, as the SSBS support will be
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* indicated to the guest and the default is
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* safe.
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*
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* Otherwise, expose a permanent mitigation
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* to the guest, and hide SSBS so that the
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* guest stays protected.
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*/
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if (cpus_have_final_cap(ARM64_SSBS))
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break;
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fallthrough;
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case SPECTRE_UNAFFECTED:
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val = SMCCC_RET_NOT_REQUIRED;
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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 = SMCCC_RET_SUCCESS;
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break;
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case SPECTRE_UNAFFECTED:
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val = 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 = SMCCC_RET_SUCCESS;
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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 = kvm_hypercall_pv_features(vcpu);
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break;
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case ARM_SMCCC_HV_PV_TIME_ST:
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gpa = kvm_init_stolen_time(vcpu);
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if (gpa != GPA_INVALID)
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val = gpa;
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break;
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default:
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return kvm_psci_call(vcpu);
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}
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smccc_set_retval(vcpu, val, 0, 0, 0);
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return 1;
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}
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