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From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Janosch Frank <frankja@linux.ibm.com>,
	David Hildenbrand <david@redhat.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 16:13:43 +0100	[thread overview]
Message-ID: <83bb5d7e-8852-476c-db9d-e673a889773e@de.ibm.com> (raw)
In-Reply-To: <58a51f40-21c7-5737-4f4c-568fdd2477fa@linux.ibm.com>



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.



  reply	other threads:[~2020-02-26 15:14 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 [this message]
2020-02-26 15:15         ` David Hildenbrand
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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