[PATCH 5.10 01/39] KVM: PPC: Book3S HV: Context tracking exit guest context before enabling irqs

From: Greg Kroah-Hartman
Date: Wed Sep 21 2022 - 12:00:37 EST


From: Nicholas Piggin <npiggin@xxxxxxxxx>

[ Upstream commit 112665286d08c87e66d699e7cba43c1497ad165f ]

Interrupts that occur in kernel mode expect that context tracking
is set to kernel. Enabling local irqs before context tracking
switches from guest to host means interrupts can come in and trigger
warnings about wrong context, and possibly worse.

Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210130130852.2952424-3-npiggin@xxxxxxxxx
Stable-dep-of: 235cee162459 ("KVM: PPC: Tick accounting should defer vtime accounting 'til after IRQ handling")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/powerpc/kvm/book3s_hv.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 38b7a3491aac..d6c4e27f7ed9 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3399,8 +3399,9 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)

kvmppc_set_host_core(pcpu);

+ guest_exit_irqoff();
+
local_irq_enable();
- guest_exit();

/* Let secondaries go back to the offline loop */
for (i = 0; i < controlled_threads; ++i) {
@@ -4235,8 +4236,9 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,

kvmppc_set_host_core(pcpu);

+ guest_exit_irqoff();
+
local_irq_enable();
- guest_exit();

cpumask_clear_cpu(pcpu, &kvm->arch.cpu_in_guest);

--
2.35.1