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 --- arch/x86/kvm/svm.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 074cd170912a..aa2da922ca99 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1794,9 +1794,25 @@ static void sev_asid_free(struct kvm *kvm) __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) @@ -1814,15 +1830,7 @@ static void sev_unbind_asid(struct kvm *kvm, unsigned int handle) 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, @@ -6475,8 +6483,10 @@ static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
/* 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;
On Mon, Jun 28, 2021 at 09:10:54PM +0000, Alper Gun wrote:
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
Message-id? Odd...
arch/x86/kvm/svm.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-)
<snip>
Can you also provide working backports for the newer kernel trees as well? We would need this in 5.10 and 5.12, right?
thanks,
greg k-h
On 05/07/21 09:15, Greg KH wrote:
On Mon, Jun 28, 2021 at 09:10:54PM +0000, Alper Gun wrote:
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
Message-id? Odd...
Not that much, see "git log -- drivers | grep Message-Id". A link to lore.kernel.org is getting more popular these days, but Message-Id is what "git am" knows about.
arch/x86/kvm/svm.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-)
<snip>
Can you also provide working backports for the newer kernel trees as well? We would need this in 5.10 and 5.12, right?
Already queued:
https://lore.kernel.org/stable/20210628141828.31757-102-sashal@kernel.org/ for 5.12 https://lore.kernel.org/stable/20210628142607.32218-94-sashal@kernel.org/ for 5.10
For this one:
Acked-by: Paolo Bonzini pbonzini@redhat.com
Paolo
On Mon, Jul 05, 2021 at 01:40:39PM +0200, Paolo Bonzini wrote:
On 05/07/21 09:15, Greg KH wrote:
On Mon, Jun 28, 2021 at 09:10:54PM +0000, Alper Gun wrote:
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
Message-id? Odd...
Not that much, see "git log -- drivers | grep Message-Id". A link to lore.kernel.org is getting more popular these days, but Message-Id is what "git am" knows about.
arch/x86/kvm/svm.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-)
<snip>
Can you also provide working backports for the newer kernel trees as well? We would need this in 5.10 and 5.12, right?
Already queued:
https://lore.kernel.org/stable/20210628141828.31757-102-sashal@kernel.org/ for 5.12 https://lore.kernel.org/stable/20210628142607.32218-94-sashal@kernel.org/ for 5.10
Ah, you are right, I forgot to update my local tree, my fault.
greg k-h
On Mon, Jun 28, 2021 at 09:10:54PM +0000, Alper Gun wrote:
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
arch/x86/kvm/svm.c | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-)
Now queued up, thanks.
greg k-h
linux-stable-mirror@lists.linaro.org