korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-13 22:56:27 +08:00
Code Issues Packages Projects Releases Wiki Activity

arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support

Browse Source 
Commit 6167ec5c91 upstream.

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 <ard.biesheuvel@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Marc Zyngier 2018-02-06 17:56:14 +00:00 committed by Greg Kroah-Hartman
parent 2cfe8929f6
commit e47273d086
4 changed files with 24 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/arm/include/asm/kvm_host.h
View File

@ -293,4 +293,10 @@ int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu,
int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr);
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__ */

5
arch/arm64/include/asm/kvm_host.h
View File

@ -384,4 +384,9 @@ static inline void __cpu_init_stage2(void)
"PARange is %d bits, unsupported configuration!", parange);
}
static inline bool kvm_arm_harden_branch_predictor(void)
{
return cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR);
}
#endif /* __ARM64_KVM_HOST_H__ */

5
include/linux/arm-smccc.h
View File

@ -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 <linux/linkage.h>

9
virt/kvm/arm/psci.c
View File

@ -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);