diff options
| author | Wei Wang <wawei@amazon.de> | 2018-11-12 12:23:14 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-08 13:03:38 +0100 |
| commit | b002e9dc214f0f917ce1b4df753c1da0b8a9ac84 (patch) | |
| tree | bf787c64f98340b11d5eaafc8871ba83d1ab6e6a /arch/x86/kvm/svm.c | |
| parent | e8693a9829d1135ff6da551023de0c707394733c (diff) | |
svm: Add mutex_lock to protect apic_access_page_done on AMD systems
commit 30510387a5e45bfcf8190e03ec7aa15b295828e2 upstream.
There is a race condition when accessing kvm->arch.apic_access_page_done.
Due to it, x86_set_memory_region will fail when creating the second vcpu
for a svm guest.
Add a mutex_lock to serialize the accesses to apic_access_page_done.
This lock is also used by vmx for the same purpose.
Signed-off-by: Wei Wang <wawei@amazon.de>
Signed-off-by: Amadeusz Juskowiak <ajusk@amazon.de>
Signed-off-by: Julian Stecklina <jsteckli@amazon.de>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kvm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 17f08db34547..4dc79d139810 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1399,20 +1399,23 @@ static u64 *avic_get_physical_id_entry(struct kvm_vcpu *vcpu, static int avic_init_access_page(struct kvm_vcpu *vcpu) { struct kvm *kvm = vcpu->kvm; - int ret; + int ret = 0; + mutex_lock(&kvm->slots_lock); if (kvm->arch.apic_access_page_done) - return 0; + goto out; - ret = x86_set_memory_region(kvm, - APIC_ACCESS_PAGE_PRIVATE_MEMSLOT, - APIC_DEFAULT_PHYS_BASE, - PAGE_SIZE); + ret = __x86_set_memory_region(kvm, + APIC_ACCESS_PAGE_PRIVATE_MEMSLOT, + APIC_DEFAULT_PHYS_BASE, + PAGE_SIZE); if (ret) - return ret; + goto out; kvm->arch.apic_access_page_done = true; - return 0; +out: + mutex_unlock(&kvm->slots_lock); + return ret; } static int avic_init_backing_page(struct kvm_vcpu *vcpu) |