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KVM: arm64: Treat PMCR_EL1.LC as RES1 on asymmetric systems

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[ Upstream commit f3c6efc72f3b20ec23566e768979802f0a398f04 ]

KVM does not support AArch32 on asymmetric systems. To that end, enforce
AArch64-only behavior on PMCR_EL1.LC when on an asymmetric system.

Fixes: 2122a833316f ("arm64: Allow mismatched 32-bit EL0 support")
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220816192554.1455559-2-oliver.upton@linux.dev
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Oliver Upton 2022-08-16 19:25:53 +00:00 committed by Greg Kroah-Hartman
parent 1b38e3b423
commit e4a36b051c
3 changed files with 7 additions and 4 deletions
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4
arch/arm64/include/asm/kvm_host.h
View File

@ -838,6 +838,10 @@ bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu);
(system_supports_mte() && \
test_bit(KVM_ARCH_FLAG_MTE_ENABLED, &(kvm)->arch.flags))
#define kvm_supports_32bit_el0() \
(system_supports_32bit_el0() && \
!static_branch_unlikely(&arm64_mismatched_32bit_el0))
int kvm_trng_call(struct kvm_vcpu *vcpu);
#ifdef CONFIG_KVM
extern phys_addr_t hyp_mem_base;

3
arch/arm64/kvm/arm.c
View File

@ -751,8 +751,7 @@ static bool vcpu_mode_is_bad_32bit(struct kvm_vcpu *vcpu)
if (likely(!vcpu_mode_is_32bit(vcpu)))
return false;
return !system_supports_32bit_el0() ||
static_branch_unlikely(&arm64_mismatched_32bit_el0);
return !kvm_supports_32bit_el0();
}
/**

4
arch/arm64/kvm/sys_regs.c
View File

@ -692,7 +692,7 @@ static void reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
*/
val = ((pmcr & ~ARMV8_PMU_PMCR_MASK)
| (ARMV8_PMU_PMCR_MASK & 0xdecafbad)) & (~ARMV8_PMU_PMCR_E);
if (!system_supports_32bit_el0())
if (!kvm_supports_32bit_el0())
val |= ARMV8_PMU_PMCR_LC;
__vcpu_sys_reg(vcpu, r->reg) = val;
}
@ -741,7 +741,7 @@ static bool access_pmcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
val = __vcpu_sys_reg(vcpu, PMCR_EL0);
val &= ~ARMV8_PMU_PMCR_MASK;
val |= p->regval & ARMV8_PMU_PMCR_MASK;
if (!system_supports_32bit_el0())
if (!kvm_supports_32bit_el0())
val |= ARMV8_PMU_PMCR_LC;
__vcpu_sys_reg(vcpu, PMCR_EL0) = val;
kvm_pmu_handle_pmcr(vcpu, val);