On 2023/10/13 4:54, Oliver Upton wrote:
From: Marc Zyngier <maz@xxxxxxxxxx>
An MMU notifier could cause us to clobber the stage-2 context loaded on
a CPU when we switch to another VM's context to invalidate. This isn't
an issue right now as the stage-2 context gets reloaded on every guest
entry, but is disastrous when moving __load_stage2() into the
vcpu_load() path.
Restore the previous stage-2 context on the way out of a TLB
invalidation if we installed something else. Deliberately do this after
TGE=1 is synchronized to keep things safe in light of the speculative AT
errata.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Oliver Upton <oliver.upton@xxxxxxxxx>
---
arch/arm64/kvm/hyp/vhe/tlb.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/hyp/vhe/tlb.c b/arch/arm64/kvm/hyp/vhe/tlb.c
index f3f2e142e4f4..ef21153ce5fa 100644
--- a/arch/arm64/kvm/hyp/vhe/tlb.c
+++ b/arch/arm64/kvm/hyp/vhe/tlb.c
@@ -11,18 +11,25 @@
#include <asm/tlbflush.h>
struct tlb_inv_context {
- unsigned long flags;
- u64 tcr;
- u64 sctlr;
+ struct kvm_s2_mmu *mmu;
+ unsigned long flags;
+ u64 tcr;
+ u64 sctlr;
};
static void __tlb_switch_to_guest(struct kvm_s2_mmu *mmu,
struct tlb_inv_context *cxt)
{
+ struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
u64 val;
local_irq_save(cxt->flags);
+ if (vcpu && mmu != vcpu->arch.hw_mmu)
+ cxt->mmu = mmu;
Shouldn't this be
cxt->mm = vcpu->arch.hw_mmu (the "previous" S2 context)?
Thanks,
Zenghui
