[PATCH 5/6] KVM: x86: Remove WARN_ON in kvm_arch_check_processor_compat

From: Chao Gao
Date: Mon Dec 27 2021 - 03:17:55 EST


kvm_arch_check_processor_compat() needn't be called with interrupt
disabled, as it only reads some CRs/MSRs which won't be clobbered
by interrupt handlers or softirq.

What really needed is disabling preemption. No additional check is
added because if CONFIG_DEBUG_PREEMPT is enabled, smp_processor_id()
(right above the WARN_ON()) can help to detect any violation.

Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>
---
arch/x86/kvm/x86.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index aa09c8792134..a80e3b0c11a8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11384,8 +11384,6 @@ int kvm_arch_check_processor_compat(void)
{
struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());

- WARN_ON(!irqs_disabled());
-
if (__cr4_reserved_bits(cpu_has, c) !=
__cr4_reserved_bits(cpu_has, &boot_cpu_data))
return -EIO;
--
2.25.1