All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dov Murik <dovmurik@linux.ibm.com>
To: Brijesh Singh <brijesh.singh@amd.com>,
	Michael Roth <michael.roth@amd.com>,
	qemu-devel@nongnu.org
Cc: "Connor Kuehl" <ckuehl@redhat.com>,
	"Philippe Mathieu-Daudé" <philmd@redhat.com>,
	"Michael S . Tsirkin" <mst@redhat.com>,
	"James Bottomley" <jejb@linux.ibm.com>,
	"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
	"Tom Lendacky" <thomas.lendacky@amd.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"David Gibson" <david@gibson.dropbear.id.au>,
	"Daniel P . Berrangé" <berrange@redhat.com>,
	kvm@vger.kernel.org, "Eduardo Habkost" <ehabkost@redhat.com>,
	"Markus Armbruster" <armbru@redhat.com>,
	"Eric Blake" <eblake@redhat.com>,
	"Dov Murik" <dovmurik@linux.ibm.com>
Subject: Re: [RFC PATCH v2 04/12] i386/sev: initialize SNP context
Date: Sun, 5 Sep 2021 20:03:21 +0300	[thread overview]
Message-ID: <f85107a8-ca12-7e93-da74-9a7a67ebc1a7@linux.ibm.com> (raw)
In-Reply-To: <7590b96e-49ec-849e-93cc-fc0346a3bada@amd.com>



On 05/09/2021 17:05, Brijesh Singh wrote:
> 
> On 9/5/21 4:19 AM, Dov Murik wrote:
>>
>> On 27/08/2021 1:26, Michael Roth wrote:
>>> From: Brijesh Singh <brijesh.singh@amd.com>
>>>
>>> When SEV-SNP is enabled, the KVM_SNP_INIT command is used to initialize
>>> the platform. The command checks whether SNP is enabled in the KVM, if
>>> enabled then it allocates a new ASID from the SNP pool and calls the
>>> firmware to initialize the all the resources.
>>>
>>
>> From the KVM code ("[PATCH Part2 v5 24/45] KVM: SVM: Add
>> KVM_SEV_SNP_LAUNCH_START command") it seems that KVM_SNP_INIT does *not*
>> allocate the ASID; actually this is done in KVM_SEV_SNP_LAUNCH_START.
> 
> Actually, the KVM_SNP_INIT does allocate the ASID. If you look at the
> driver code then in switch state, the SNP_INIT fallthrough to SEV_INIT
> which will call sev_guest_init(). The sev_guest_init() allocates a new
> ASID.
> https://github.com/AMDESE/linux/blob/bb9ba49cd9b749d5551aae295c091d8757153dd7/arch/x86/kvm/svm/sev.c#L255
> 
> The LAUNCH_START simply binds the ASID to a guest.

OK thank you for clearing this up.  So the kernel is choosing the new
ASID during the KVM_SNP_INIT ioctl, but doesn't "tell" the firmware
about it.  Then later in SNP_LAUNCH_START that integer (saved in the
kernel sev structure) is given to the firmware as an argument of the
SNP_LAUNCH_START (binding?).  Is this description correct?


-Dov

WARNING: multiple messages have this Message-ID (diff)
From: Dov Murik <dovmurik@linux.ibm.com>
To: Brijesh Singh <brijesh.singh@amd.com>,
	Michael Roth <michael.roth@amd.com>,
	qemu-devel@nongnu.org
Cc: "Tom Lendacky" <thomas.lendacky@amd.com>,
	"Daniel P . Berrangé" <berrange@redhat.com>,
	"Eduardo Habkost" <ehabkost@redhat.com>,
	kvm@vger.kernel.org, "Michael S . Tsirkin" <mst@redhat.com>,
	"Connor Kuehl" <ckuehl@redhat.com>,
	"Eric Blake" <eblake@redhat.com>,
	"James Bottomley" <jejb@linux.ibm.com>,
	"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
	"Markus Armbruster" <armbru@redhat.com>,
	"Dov Murik" <dovmurik@linux.ibm.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Philippe Mathieu-Daudé" <philmd@redhat.com>,
	"David Gibson" <david@gibson.dropbear.id.au>
Subject: Re: [RFC PATCH v2 04/12] i386/sev: initialize SNP context
Date: Sun, 5 Sep 2021 20:03:21 +0300	[thread overview]
Message-ID: <f85107a8-ca12-7e93-da74-9a7a67ebc1a7@linux.ibm.com> (raw)
In-Reply-To: <7590b96e-49ec-849e-93cc-fc0346a3bada@amd.com>



On 05/09/2021 17:05, Brijesh Singh wrote:
> 
> On 9/5/21 4:19 AM, Dov Murik wrote:
>>
>> On 27/08/2021 1:26, Michael Roth wrote:
>>> From: Brijesh Singh <brijesh.singh@amd.com>
>>>
>>> When SEV-SNP is enabled, the KVM_SNP_INIT command is used to initialize
>>> the platform. The command checks whether SNP is enabled in the KVM, if
>>> enabled then it allocates a new ASID from the SNP pool and calls the
>>> firmware to initialize the all the resources.
>>>
>>
>> From the KVM code ("[PATCH Part2 v5 24/45] KVM: SVM: Add
>> KVM_SEV_SNP_LAUNCH_START command") it seems that KVM_SNP_INIT does *not*
>> allocate the ASID; actually this is done in KVM_SEV_SNP_LAUNCH_START.
> 
> Actually, the KVM_SNP_INIT does allocate the ASID. If you look at the
> driver code then in switch state, the SNP_INIT fallthrough to SEV_INIT
> which will call sev_guest_init(). The sev_guest_init() allocates a new
> ASID.
> https://github.com/AMDESE/linux/blob/bb9ba49cd9b749d5551aae295c091d8757153dd7/arch/x86/kvm/svm/sev.c#L255
> 
> The LAUNCH_START simply binds the ASID to a guest.

OK thank you for clearing this up.  So the kernel is choosing the new
ASID during the KVM_SNP_INIT ioctl, but doesn't "tell" the firmware
about it.  Then later in SNP_LAUNCH_START that integer (saved in the
kernel sev structure) is given to the firmware as an argument of the
SNP_LAUNCH_START (binding?).  Is this description correct?


-Dov


  reply	other threads:[~2021-09-05 17:04 UTC|newest]

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-26 22:26 [RFC PATCH v2 00/12] Add AMD Secure Nested Paging (SEV-SNP) support Michael Roth
2021-08-26 22:26 ` [RFC PATCH v2 01/12] i386/sev: introduce "sev-common" type to encapsulate common SEV state Michael Roth
2021-09-01 14:18   ` Markus Armbruster
2021-09-03 15:11     ` Michael Roth
2021-08-26 22:26 ` [RFC PATCH v2 02/12] linux-header: add the SNP specific command Michael Roth
2021-09-03 20:36   ` Dov Murik
2021-09-03 20:36     ` Dov Murik
2021-09-07 14:27     ` Michael Roth
2021-08-26 22:26 ` [RFC PATCH v2 03/12] i386/sev: introduce 'sev-snp-guest' object Michael Roth
2021-09-01 14:29   ` Markus Armbruster
2021-09-03 15:15     ` Michael Roth
2021-09-03 21:12   ` Dov Murik
2021-09-03 21:12     ` Dov Murik
2021-09-07 14:20     ` Michael Roth
2021-08-26 22:26 ` [RFC PATCH v2 04/12] i386/sev: initialize SNP context Michael Roth
2021-09-05  7:07   ` Dov Murik
2021-09-05  7:07     ` Dov Murik
2021-09-05 13:58     ` Brijesh Singh
2021-09-05 17:09       ` Dov Murik
2021-09-05 17:09         ` Dov Murik
2021-09-05  9:19   ` Dov Murik
2021-09-05  9:19     ` Dov Murik
2021-09-05 14:05     ` Brijesh Singh
2021-09-05 17:03       ` Dov Murik [this message]
2021-09-05 17:03         ` Dov Murik
2021-08-26 22:26 ` [RFC PATCH v2 05/12] i386/sev: add the SNP launch start context Michael Roth
2021-08-26 22:26 ` [RFC PATCH v2 06/12] i386/sev: add support to encrypt BIOS when SEV-SNP is enabled Michael Roth
2021-08-26 22:26 ` [RFC PATCH v2 07/12] i386/sev: populate secrets and cpuid page and finalize the SNP launch Michael Roth
2021-09-03 20:24   ` Dov Murik
2021-09-03 20:24     ` Dov Murik
2021-09-07 16:18     ` Michael Roth
2021-08-26 22:26 ` [RFC PATCH v2 08/12] target/i386: set SEV-SNP CPUID bit when SNP enabled Michael Roth
2021-08-26 22:26 ` [RFC PATCH v2 09/12] target/i386: allow versioned CPUs to specify new cache_info Michael Roth
2021-08-26 22:26 ` [RFC PATCH v2 10/12] target/i386: add new EPYC CPU versions with updated cache_info Michael Roth
2021-08-26 22:26 ` [RFC PATCH v2 11/12] i386/sev: sev-snp: add support for CPUID validation Michael Roth
2021-09-05 10:02   ` Dov Murik
2021-09-05 10:02     ` Dov Murik
2021-09-07 16:50     ` Michael Roth
2021-09-07 17:44       ` Dov Murik
2021-09-07 17:44         ` Dov Murik
2021-08-26 22:26 ` [RFC PATCH v2 12/12] i386/sev: update query-sev QAPI format to handle SEV-SNP Michael Roth
2021-09-01 14:14   ` Markus Armbruster
2021-09-03 15:13     ` Michael Roth
2021-09-03 15:30       ` Daniel P. Berrangé
2021-09-03 15:30         ` Daniel P. Berrangé
2021-09-03 15:43         ` Michael Roth
2021-09-03 15:43           ` Michael Roth via
2021-09-03 15:58           ` Daniel P. Berrangé
2021-09-03 15:58             ` Daniel P. Berrangé
2021-09-03 16:01     ` Daniel P. Berrangé
2021-09-03 16:01       ` Daniel P. Berrangé
2021-09-04  5:41       ` Markus Armbruster
2021-09-07 11:52       ` Dr. David Alan Gilbert
2021-09-07 11:52         ` Dr. David Alan Gilbert
2021-09-07 14:33         ` Michael Roth
2021-09-07 14:33           ` Michael Roth via
2021-09-03 15:27   ` Daniel P. Berrangé
2021-09-03 15:27     ` Daniel P. Berrangé
2021-11-16  9:23 ` [RFC PATCH v2 00/12] Add AMD Secure Nested Paging (SEV-SNP) support Daniel P. Berrangé
2021-11-16  9:23   ` Daniel P. Berrangé
2021-11-16 11:54   ` Brijesh Singh

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=f85107a8-ca12-7e93-da74-9a7a67ebc1a7@linux.ibm.com \
    --to=dovmurik@linux.ibm.com \
    --cc=armbru@redhat.com \
    --cc=berrange@redhat.com \
    --cc=brijesh.singh@amd.com \
    --cc=ckuehl@redhat.com \
    --cc=david@gibson.dropbear.id.au \
    --cc=dgilbert@redhat.com \
    --cc=eblake@redhat.com \
    --cc=ehabkost@redhat.com \
    --cc=jejb@linux.ibm.com \
    --cc=kvm@vger.kernel.org \
    --cc=michael.roth@amd.com \
    --cc=mst@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=philmd@redhat.com \
    --cc=qemu-devel@nongnu.org \
    --cc=thomas.lendacky@amd.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.