From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Thu, 8 Jul 2021 18:39:31 +0000 (+0200)
Subject: 4.19-stable patches
X-Git-Tag: v4.4.275~4
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=675cea6f2c937a12b861f89107c868ed809115a3;p=thirdparty%2Fkernel%2Fstable-queue.git

4.19-stable patches

added patches:
	kvm-svm-call-sev-guest-decommission-if-asid-binding-fails.patch
---

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
index 00000000000..5a439e2599b
--- /dev/null
+++ b/queue-4.19/kvm-svm-call-sev-guest-decommission-if-asid-binding-fails.patch
@@ -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;
diff --git a/queue-4.19/series b/queue-4.19/series
index 9101833ab57..722498bf9cd 100644
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -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