[v2,2/5] arm64: KVM: Reorder system register restoration and stage-2 activation
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Message ID 20191019095521.31722-3-maz@kernel.org
State New
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Series
  • arm64: KVM: Add workaround for errata 1319367 and 1319537
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Commit Message

Marc Zyngier Oct. 19, 2019, 9:55 a.m. UTC
In order to prepare for handling erratum 1319367, we need to make
sure that all system registers (and most importantly the registers
configuring the virtual memory) are set before we enable stage-2
translation.

This results in a minor reorganisation of the load sequence, without
any functional change.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/hyp/switch.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

Comments

James Morse Oct. 24, 2019, 4:09 p.m. UTC | #1
Hi Marc,

On 19/10/2019 10:55, Marc Zyngier wrote:
> In order to prepare for handling erratum 1319367, we need to make
> sure that all system registers (and most importantly the registers
> configuring the virtual memory) are set before we enable stage-2
> translation.
> 
> This results in a minor reorganisation of the load sequence, without
> any functional change.

Reviewed-by: James Morse <james.morse@arm.com>


Thanks,

James

Patch
diff mbox series

diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 3d3815020e36..69e10b29cbd0 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -605,18 +605,23 @@  int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu)
 
 	__sysreg_save_state_nvhe(host_ctxt);
 
-	__activate_vm(kern_hyp_va(vcpu->kvm));
-	__activate_traps(vcpu);
-
-	__hyp_vgic_restore_state(vcpu);
-	__timer_enable_traps(vcpu);
-
 	/*
 	 * We must restore the 32-bit state before the sysregs, thanks
 	 * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72).
+	 *
+	 * Also, and in order to be able to deal with erratum #1319537 (A57)
+	 * and #1319367 (A72), we must ensure that all VM-related sysreg are
+	 * restored before we enable S2 translation.
 	 */
 	__sysreg32_restore_state(vcpu);
 	__sysreg_restore_state_nvhe(guest_ctxt);
+
+	__activate_vm(kern_hyp_va(vcpu->kvm));
+	__activate_traps(vcpu);
+
+	__hyp_vgic_restore_state(vcpu);
+	__timer_enable_traps(vcpu);
+
 	__debug_switch_to_guest(vcpu);
 
 	__set_guest_arch_workaround_state(vcpu);