]> git.ipfire.org Git - thirdparty/kernel/stable-queue.git/commitdiff
4.19-stable patches
authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 8 Jul 2021 18:39:31 +0000 (20:39 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 8 Jul 2021 18:39:31 +0000 (20:39 +0200)
added patches:
kvm-svm-call-sev-guest-decommission-if-asid-binding-fails.patch

queue-4.19/kvm-svm-call-sev-guest-decommission-if-asid-binding-fails.patch [new file with mode: 0644]
queue-4.19/series

diff --git a/queue-4.19/kvm-svm-call-sev-guest-decommission-if-asid-binding-fails.patch b/queue-4.19/kvm-svm-call-sev-guest-decommission-if-asid-binding-fails.patch
new file mode 100644 (file)
index 0000000..5a439e2
--- /dev/null
@@ -0,0 +1,93 @@
+From 934002cd660b035b926438244b4294e647507e13 Mon Sep 17 00:00:00 2001
+From: Alper Gun <alpergun@google.com>
+Date: Thu, 10 Jun 2021 17:46:04 +0000
+Subject: KVM: SVM: Call SEV Guest Decommission if ASID binding fails
+
+From: Alper Gun <alpergun@google.com>
+
+commit 934002cd660b035b926438244b4294e647507e13 upstream.
+
+Send SEV_CMD_DECOMMISSION command to PSP firmware if ASID binding
+fails. If a failure happens after  a successful LAUNCH_START command,
+a decommission command should be executed. Otherwise, guest context
+will be unfreed inside the AMD SP. After the firmware will not have
+memory to allocate more SEV guest context, LAUNCH_START command will
+begin to fail with SEV_RET_RESOURCE_LIMIT error.
+
+The existing code calls decommission inside sev_unbind_asid, but it is
+not called if a failure happens before guest activation succeeds. If
+sev_bind_asid fails, decommission is never called. PSP firmware has a
+limit for the number of guests. If sev_asid_binding fails many times,
+PSP firmware will not have resources to create another guest context.
+
+Cc: stable@vger.kernel.org
+Fixes: 59414c989220 ("KVM: SVM: Add support for KVM_SEV_LAUNCH_START command")
+Reported-by: Peter Gonda <pgonda@google.com>
+Signed-off-by: Alper Gun <alpergun@google.com>
+Reviewed-by: Marc Orr <marcorr@google.com>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Message-Id: <20210610174604.2554090-1-alpergun@google.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/x86/kvm/svm.c |   32 +++++++++++++++++++++-----------
+ 1 file changed, 21 insertions(+), 11 deletions(-)
+
+--- a/arch/x86/kvm/svm.c
++++ b/arch/x86/kvm/svm.c
+@@ -1791,9 +1791,25 @@ static void sev_asid_free(struct kvm *kv
+       __sev_asid_free(sev->asid);
+ }
+-static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
++static void sev_decommission(unsigned int handle)
+ {
+       struct sev_data_decommission *decommission;
++
++      if (!handle)
++              return;
++
++      decommission = kzalloc(sizeof(*decommission), GFP_KERNEL);
++      if (!decommission)
++              return;
++
++      decommission->handle = handle;
++      sev_guest_decommission(decommission, NULL);
++
++      kfree(decommission);
++}
++
++static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
++{
+       struct sev_data_deactivate *data;
+       if (!handle)
+@@ -1811,15 +1827,7 @@ static void sev_unbind_asid(struct kvm *
+       sev_guest_df_flush(NULL);
+       kfree(data);
+-      decommission = kzalloc(sizeof(*decommission), GFP_KERNEL);
+-      if (!decommission)
+-              return;
+-
+-      /* decommission handle */
+-      decommission->handle = handle;
+-      sev_guest_decommission(decommission, NULL);
+-
+-      kfree(decommission);
++      sev_decommission(handle);
+ }
+ static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr,
+@@ -6469,8 +6477,10 @@ static int sev_launch_start(struct kvm *
+       /* Bind ASID to this guest */
+       ret = sev_bind_asid(kvm, start->handle, error);
+-      if (ret)
++      if (ret) {
++              sev_decommission(start->handle);
+               goto e_free_session;
++      }
+       /* return handle to userspace */
+       params.handle = start->handle;
index 9101833ab57dabe6361e9ee2643acc208775ab23..722498bf9cdd2384e795458c88c284b64770989b 100644 (file)
@@ -27,3 +27,4 @@ arm-dts-imx6qdl-sabresd-remove-incorrect-power-supply-assignment.patch
 kthread_worker-split-code-for-canceling-the-delayed-work-timer.patch
 kthread-prevent-deadlock-when-kthread_mod_delayed_work-races-with-kthread_cancel_delayed_work_sync.patch
 xen-events-reset-active-flag-for-lateeoi-events-later.patch
+kvm-svm-call-sev-guest-decommission-if-asid-binding-fails.patch