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authorVitaly Kuznetsov <vkuznets@redhat.com>2020-04-01 10:13:48 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-04-17 10:48:48 +0200
commitf9971a898a815c2a6cce2932e91a576b28ed4cce (patch)
treeefef17f9c78bb9b8c023e1ea3bb61edaacec4ea9 /arch/x86
parent4538f42a825cc33c7eabbbd5abf82c1ad72ec798 (diff)
KVM: VMX: fix crash cleanup when KVM wasn't used
commit dbef2808af6c594922fe32833b30f55f35e9da6d upstream. If KVM wasn't used at all before we crash the cleanup procedure fails with BUG: unable to handle page fault for address: ffffffffffffffc8 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 23215067 P4D 23215067 PUD 23217067 PMD 0 Oops: 0000 [#8] SMP PTI CPU: 0 PID: 3542 Comm: bash Kdump: loaded Tainted: G D 5.6.0-rc2+ #823 RIP: 0010:crash_vmclear_local_loaded_vmcss.cold+0x19/0x51 [kvm_intel] The root cause is that loaded_vmcss_on_cpu list is not yet initialized, we initialize it in hardware_enable() but this only happens when we start a VM. Previously, we used to have a bitmap with enabled CPUs and that was preventing [masking] the issue. Initialized loaded_vmcss_on_cpu list earlier, right before we assign crash_vmclear_loaded_vmcss pointer. blocked_vcpu_on_cpu list and blocked_vcpu_on_cpu_lock are moved altogether for consistency. Fixes: 31603d4fc2bb ("KVM: VMX: Always VMCLEAR in-use VMCSes during crash with kexec support") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200401081348.1345307-1-vkuznets@redhat.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/vmx.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 47501e3b0ca0..d37b48173e9c 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -4398,10 +4398,6 @@ static int hardware_enable(void)
!hv_get_vp_assist_page(cpu))
return -EFAULT;
- INIT_LIST_HEAD(&per_cpu(loaded_vmcss_on_cpu, cpu));
- INIT_LIST_HEAD(&per_cpu(blocked_vcpu_on_cpu, cpu));
- spin_lock_init(&per_cpu(blocked_vcpu_on_cpu_lock, cpu));
-
rdmsrl(MSR_IA32_FEATURE_CONTROL, old);
test_bits = FEATURE_CONTROL_LOCKED;
@@ -14554,7 +14550,7 @@ module_exit(vmx_exit);
static int __init vmx_init(void)
{
- int r;
+ int r, cpu;
#if IS_ENABLED(CONFIG_HYPERV)
/*
@@ -14605,6 +14601,12 @@ static int __init vmx_init(void)
}
}
+ for_each_possible_cpu(cpu) {
+ INIT_LIST_HEAD(&per_cpu(loaded_vmcss_on_cpu, cpu));
+ INIT_LIST_HEAD(&per_cpu(blocked_vcpu_on_cpu, cpu));
+ spin_lock_init(&per_cpu(blocked_vcpu_on_cpu_lock, cpu));
+ }
+
#ifdef CONFIG_KEXEC_CORE
rcu_assign_pointer(crash_vmclear_loaded_vmcss,
crash_vmclear_local_loaded_vmcss);