From: Kirill A. Shutemov Date: Tue, 5 Dec 2023 00:45:01 +0000 (+0300) Subject: x86/kvm: Do not try to disable kvmclock if it was not enabled X-Git-Tag: v6.6.17~941 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=db448ac982e43cb4ce8d0995f26fc46388e01760;p=platform%2Fkernel%2Flinux-rpi.git x86/kvm: Do not try to disable kvmclock if it was not enabled commit 1c6d984f523f67ecfad1083bb04c55d91977bb15 upstream. kvm_guest_cpu_offline() tries to disable kvmclock regardless if it is present in the VM. It leads to write to a MSR that doesn't exist on some configurations, namely in TDX guest: unchecked MSR access error: WRMSR to 0x12 (tried to write 0x0000000000000000) at rIP: 0xffffffff8110687c (kvmclock_disable+0x1c/0x30) kvmclock enabling is gated by CLOCKSOURCE and CLOCKSOURCE2 KVM paravirt features. Do not disable kvmclock if it was not enabled. Signed-off-by: Kirill A. Shutemov Fixes: c02027b5742b ("x86/kvm: Disable kvmclock on all CPUs on shutdown") Reviewed-by: Sean Christopherson Reviewed-by: Vitaly Kuznetsov Cc: Paolo Bonzini Cc: Wanpeng Li Cc: stable@vger.kernel.org Message-Id: <20231205004510.27164-6-kirill.shutemov@linux.intel.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index fb8f5214..f2fff62 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -24,8 +24,8 @@ static int kvmclock __initdata = 1; static int kvmclock_vsyscall __initdata = 1; -static int msr_kvm_system_time __ro_after_init = MSR_KVM_SYSTEM_TIME; -static int msr_kvm_wall_clock __ro_after_init = MSR_KVM_WALL_CLOCK; +static int msr_kvm_system_time __ro_after_init; +static int msr_kvm_wall_clock __ro_after_init; static u64 kvm_sched_clock_offset __ro_after_init; static int __init parse_no_kvmclock(char *arg) @@ -195,7 +195,8 @@ static void kvm_setup_secondary_clock(void) void kvmclock_disable(void) { - native_write_msr(msr_kvm_system_time, 0, 0); + if (msr_kvm_system_time) + native_write_msr(msr_kvm_system_time, 0, 0); } static void __init kvmclock_init_mem(void) @@ -294,7 +295,10 @@ void __init kvmclock_init(void) if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE2)) { msr_kvm_system_time = MSR_KVM_SYSTEM_TIME_NEW; msr_kvm_wall_clock = MSR_KVM_WALL_CLOCK_NEW; - } else if (!kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE)) { + } else if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE)) { + msr_kvm_system_time = MSR_KVM_SYSTEM_TIME; + msr_kvm_wall_clock = MSR_KVM_WALL_CLOCK; + } else { return; }