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| author | Marc Zyngier <maz@kernel.org> | 2021-03-17 19:50:39 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2021-03-18 17:22:31 +0300 |
| commit | beed09067b428a7e84a53b05c1de1f93c8460e91 (patch) | |
| tree | b1191fec23fd574d4eb8d17ffc22453bc66217a5 /arch/arm64/kvm/hyp/nvhe/switch.c | |
| parent | b145a8437aab2799969f6ad8e384b557872333c2 (diff) | |
| download | linux-beed09067b428a7e84a53b05c1de1f93c8460e91.tar.xz | |
KVM: arm64: Trap host SVE accesses when the FPSIMD state is dirty
ZCR_EL2 controls the upper bound for ZCR_EL1, and is set to
a potentially lower limit when the guest uses SVE. In order
to restore the SVE state on the EL1 host, we must first
reset ZCR_EL2 to its original value.
To make it as lazy as possible on the EL1 host side, set
the SVE trapping in place when exiting from the guest.
On the first EL1 access to SVE, ZCR_EL2 will be restored
to its full glory.
Suggested-by: Andrew Scull <ascull@google.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/switch.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/switch.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index f3d0e9eca56c..60adc7ff4caa 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -68,7 +68,7 @@ static void __activate_traps(struct kvm_vcpu *vcpu) static void __deactivate_traps(struct kvm_vcpu *vcpu) { extern char __kvm_hyp_host_vector[]; - u64 mdcr_el2; + u64 mdcr_el2, cptr; ___deactivate_traps(vcpu); @@ -101,7 +101,12 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu) write_sysreg(HCR_HOST_NVHE_PROTECTED_FLAGS, hcr_el2); else write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2); - write_sysreg(CPTR_EL2_DEFAULT, cptr_el2); + + cptr = CPTR_EL2_DEFAULT; + if (vcpu_has_sve(vcpu) && (vcpu->arch.flags & KVM_ARM64_FP_ENABLED)) + cptr |= CPTR_EL2_TZ; + + write_sysreg(cptr, cptr_el2); write_sysreg(__kvm_hyp_host_vector, vbar_el2); } |