summaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorWei Wang <wawei@amazon.de>2018-11-12 15:23:14 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-12-08 15:03:38 +0300
commitb002e9dc214f0f917ce1b4df753c1da0b8a9ac84 (patch)
treebf787c64f98340b11d5eaafc8871ba83d1ab6e6a /arch
parente8693a9829d1135ff6da551023de0c707394733c (diff)
downloadlinux-b002e9dc214f0f917ce1b4df753c1da0b8a9ac84.tar.xz
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')
-rw-r--r--arch/x86/kvm/svm.c19
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)