From: David Hildenbrand <david@redhat.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>,
Janosch Frank <frankja@linux.ibm.com>,
qemu-devel@nongnu.org
Cc: qemu-s390x@nongnu.org, cohuck@redhat.com
Subject: Re: [PATCH v5 07/18] s390x: protvirt: Inhibit balloon when switching to protected mode
Date: Wed, 26 Feb 2020 16:15:48 +0100 [thread overview]
Message-ID: <8634143d-146c-bf15-b084-8470db2e72a6@redhat.com> (raw)
In-Reply-To: <83bb5d7e-8852-476c-db9d-e673a889773e@de.ibm.com>
On 26.02.20 16:13, Christian Borntraeger wrote:
>
>
> On 26.02.20 16:11, Janosch Frank wrote:
>> On 2/26/20 3:59 PM, David Hildenbrand wrote:
>>> On 26.02.20 13:20, Janosch Frank wrote:
>>>> Ballooning in protected VMs can only be done when the guest shares the
>>>> pages it gives to the host. Hence, until we have a solution for this
>>>> in the guest kernel, we inhibit ballooning when switching into
>>>> protected mode and reverse that once we move out of it.
>>>
>>> I don't understand what you mean here, sorry. zapping a page will mean
>>> that a fresh one will be faulted in when accessed. And AFAIK, that means
>>> it will be encrypted again when needed.
>>
>> Yes, as soon as the host alters non-shared memory we'll run into
>> integrity issues.
>>
>>
>> I've been talking to Halil after I sent this out and it looks like we'll
>> rather try to automatically enable the IOMMU for all devices when
>> switching into protected mode. He said that if the IOMMU is set the
>> balloon code will do an early exit on feature negotiation.
>
> I think we should fence the balloon here nevertheless, so the patch in
> itself is probably fine.
+1, this is a global "don't use ram_block_discard" trigger.
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2020-02-26 15:16 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-26 12:20 [PATCH v5 00/18] s390x: Protected Virtualization support Janosch Frank
2020-02-26 12:20 ` [PATCH v5 01/18] s390x: Use constant for ESA PSW address Janosch Frank
2020-02-26 13:46 ` Christian Borntraeger
2020-02-26 13:47 ` Janosch Frank
2020-02-26 14:27 ` David Hildenbrand
2020-02-26 17:51 ` Cornelia Huck
2020-02-26 17:52 ` David Hildenbrand
2020-02-27 7:53 ` Janosch Frank
2020-02-27 8:09 ` Janosch Frank
2020-02-27 9:06 ` Cornelia Huck
2020-02-27 9:23 ` [PATCH v6] s390x: Rename and use constants for short PSW address and mask Janosch Frank
2020-02-27 9:27 ` David Hildenbrand
2020-02-27 10:36 ` Cornelia Huck
2020-02-26 12:20 ` [PATCH v5 02/18] Sync pv Janosch Frank
2020-02-26 12:20 ` [PATCH v5 03/18] s390x: protvirt: Add diag308 subcodes 8 - 10 Janosch Frank
2020-02-26 12:20 ` [PATCH v5 04/18] s390x: protvirt: Support unpack facility Janosch Frank
2020-02-26 12:20 ` [PATCH v5 05/18] s390x: protvirt: Add migration blocker Janosch Frank
2020-02-26 14:05 ` Christian Borntraeger
2020-02-26 14:08 ` Janosch Frank
2020-02-26 12:20 ` [PATCH v5 06/18] s390x: protvirt: Handle diag 308 subcodes 0,1,3,4 Janosch Frank
2020-02-26 15:00 ` Christian Borntraeger
2020-02-26 15:11 ` Janosch Frank
2020-02-26 12:20 ` [PATCH v5 07/18] s390x: protvirt: Inhibit balloon when switching to protected mode Janosch Frank
2020-02-26 14:59 ` David Hildenbrand
2020-02-26 15:06 ` Christian Borntraeger
2020-02-26 15:16 ` David Hildenbrand
2020-02-26 15:30 ` Janosch Frank
2020-02-26 15:31 ` David Hildenbrand
2020-02-26 18:24 ` Cornelia Huck
2020-03-03 12:42 ` Christian Borntraeger
2020-02-26 15:11 ` Janosch Frank
2020-02-26 15:13 ` Christian Borntraeger
2020-02-26 15:15 ` David Hildenbrand [this message]
2020-02-27 12:24 ` Halil Pasic
2020-03-19 13:42 ` Halil Pasic
2020-03-19 13:54 ` David Hildenbrand
2020-03-19 15:40 ` Halil Pasic
2020-03-19 17:31 ` David Hildenbrand
2020-03-20 18:43 ` Halil Pasic
2020-03-24 21:07 ` Brijesh Singh
2020-03-27 10:50 ` David Hildenbrand
2020-03-19 17:45 ` Michael S. Tsirkin
2020-03-20 9:36 ` David Hildenbrand
2020-03-29 14:48 ` Michael S. Tsirkin
2020-03-31 8:59 ` David Hildenbrand
2020-02-26 12:20 ` [PATCH v5 08/18] s390x: protvirt: KVM intercept changes Janosch Frank
2020-02-26 12:20 ` [PATCH v5 09/18] s390x: Add SIDA memory ops Janosch Frank
2020-02-26 12:20 ` [PATCH v5 10/18] s390x: protvirt: Move STSI data over SIDAD Janosch Frank
2020-02-26 12:20 ` [PATCH v5 11/18] s390x: protvirt: SCLP interpretation Janosch Frank
2020-02-26 12:20 ` [PATCH v5 12/18] s390x: protvirt: Set guest IPL PSW Janosch Frank
2020-02-26 12:20 ` [PATCH v5 13/18] s390x: protvirt: Move diag 308 data over SIDAD Janosch Frank
2020-02-26 12:20 ` [PATCH v5 14/18] s390x: protvirt: Disable address checks for PV guest IO emulation Janosch Frank
2020-02-26 12:20 ` [PATCH v5 15/18] s390x: protvirt: Move IO control structures over SIDA Janosch Frank
2020-02-26 12:20 ` [PATCH v5 16/18] s390x: protvirt: Handle SIGP store status correctly Janosch Frank
2020-02-26 12:20 ` [PATCH v5 17/18] s390x: Add unpack facility feature to GA1 Janosch Frank
2020-02-26 12:20 ` [PATCH v5 18/18] docs: Add protvirt docs Janosch Frank
2020-02-26 20:09 ` [PATCH v5 00/18] s390x: Protected Virtualization support Cornelia Huck
2020-02-27 8:32 ` Janosch Frank
2020-03-03 15:50 ` [PATCH] pc-bios: s390x: Save iplb location in lowcore Janosch Frank
2020-03-03 16:13 ` David Hildenbrand
2020-03-04 8:59 ` Janosch Frank
2020-03-04 9:05 ` David Hildenbrand
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