From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>,
Janosch Frank <frankja@linux.vnet.ibm.com>
Cc: KVM <kvm@vger.kernel.org>, Cornelia Huck <cohuck@redhat.com>,
David Hildenbrand <david@redhat.com>,
Thomas Huth <thuth@redhat.com>,
Ulrich Weigand <Ulrich.Weigand@de.ibm.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
Andrea Arcangeli <aarcange@redhat.com>
Subject: [RFCv2 01/37] DOCUMENTATION: protvirt: Protected virtual machine introduction
Date: Mon, 3 Feb 2020 08:19:21 -0500 [thread overview]
Message-ID: <20200203131957.383915-2-borntraeger@de.ibm.com> (raw)
In-Reply-To: <20200203131957.383915-1-borntraeger@de.ibm.com>
From: Janosch Frank <frankja@linux.ibm.com>
Add documentation about protected KVM guests.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
Documentation/virt/kvm/s390-pv.rst | 103 +++++++++++++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 104 insertions(+)
create mode 100644 Documentation/virt/kvm/s390-pv.rst
diff --git a/Documentation/virt/kvm/s390-pv.rst b/Documentation/virt/kvm/s390-pv.rst
new file mode 100644
index 000000000000..5ef7e6cc2180
--- /dev/null
+++ b/Documentation/virt/kvm/s390-pv.rst
@@ -0,0 +1,103 @@
+.. SPDX-License-Identifier: GPL-2.0
+============================
+Ultravisor and Protected VMs
+============================
+
+Summary
+-------
+Protected virtual machines (PVM) are KVM VMs, where KVM can't access
+the VM's state like guest memory and guest registers anymore. Instead,
+the PVMs are mostly managed by a new entity called Ultravisor
+(UV). The UV provides an API that can be used by PVMs and KVM to
+request management actions.
+
+Each guest starts in the non-protected mode and then may make a
+request to transition into protected mode. On transition, KVM
+registers the guest and its VCPUs with the Ultravisor and prepares
+everything for running it.
+
+The Ultravisor will secure and decrypt the guest's boot memory
+(i.e. kernel/initrd). It will safeguard state changes like VCPU
+starts/stops and injected interrupts while the guest is running.
+
+As access to the guest's state, such as the SIE state description, is
+normally needed to be able to run a VM, some changes have been made in
+SIE behavior. A new format 4 state description has been introduced,
+where some fields have different meanings for a PVM. SIE exits are
+minimized as much as possible to improve speed and reduce exposed
+guest state.
+
+
+Interrupt injection
+-------------------
+Interrupt injection is safeguarded by the Ultravisor. As KVM doesn't
+have access to the VCPUs' lowcores, injection is handled via the
+format 4 state description.
+
+Machine check, external, IO and restart interruptions each can be
+injected on SIE entry via a bit in the interrupt injection control
+field (offset 0x54). If the guest cpu is not enabled for the interrupt
+at the time of injection, a validity interception is recognized. The
+format 4 state description contains fields in the interception data
+block where data associated with the interrupt can be transported.
+
+Program and Service Call exceptions have another layer of
+safeguarding; they can only be injected for instructions that have
+been intercepted into KVM. The exceptions need to be a valid outcome
+of an instruction emulation by KVM, e.g. we can never inject a
+addressing exception as they are reported by SIE since KVM has no
+access to the guest memory.
+
+
+Mask notification interceptions
+-------------------------------
+As a replacement for the lctl(g) and lpsw(e) instruction
+interceptions, two new interception codes have been introduced. One
+indicating that the contents of CRs 0, 6 or 14 have been changed. And
+one indicating PSW bit 13 changes.
+
+Instruction emulation
+---------------------
+With the format 4 state description for PVMs, the SIE instruction already
+interprets more instructions than it does with format 2. As it is not
+able to interpret every instruction, the SIE and the UV safeguard KVM's
+emulation inputs and outputs.
+
+Guest GRs and most of the instruction data, such as I/O data structures,
+are filtered. Instruction data is copied to and from the Secure
+Instruction Data Area. Guest GRs are put into / retrieved from the
+Interception-Data block.
+
+The Interception-Data block from the state description's offset 0x380
+contains GRs 0 - 16. Only GR values needed to emulate an instruction
+will be copied into this area.
+
+The Interception Parameters state description field still contains the
+the bytes of the instruction text, but with pre-set register values
+instead of the actual ones. I.e. each instruction always uses the same
+instruction text, in order not to leak guest instruction text.
+
+The Secure Instruction Data Area contains instruction storage
+data. Instruction data, i.e. data being referenced by an instruction
+like the SCCB for sclp, is moved over the SIDA When an instruction is
+intercepted, the SIE will only allow data and program interrupts for
+this instruction to be moved to the guest via the two data areas
+discussed before. Other data is either ignored or results in validity
+interceptions.
+
+
+Instruction emulation interceptions
+-----------------------------------
+There are two types of SIE secure instruction intercepts: the normal
+and the notification type. Normal secure instruction intercepts will
+make the guest pending for instruction completion of the intercepted
+instruction type, i.e. on SIE entry it is attempted to complete
+emulation of the instruction with the data provided by KVM. That might
+be a program exception or instruction completion.
+
+The notification type intercepts inform KVM about guest environment
+changes due to guest instruction interpretation. Such an interception
+is recognized for example for the store prefix instruction to provide
+the new lowcore location. On SIE reentry, any KVM data in the data
+areas is ignored, program exceptions are not injected and execution
+continues, as if no intercept had happened.
diff --git a/MAINTAINERS b/MAINTAINERS
index 56765f542244..90da412bebd9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9106,6 +9106,7 @@ L: kvm@vger.kernel.org
W: http://www.ibm.com/developerworks/linux/linux390/
T: git git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git
S: Supported
+F: Documentation/virt/kvm/s390*
F: arch/s390/include/uapi/asm/kvm*
F: arch/s390/include/asm/gmap.h
F: arch/s390/include/asm/kvm*
--
2.24.0
next prev parent reply other threads:[~2020-02-03 13:20 UTC|newest]
Thread overview: 200+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-03 13:19 [RFCv2 00/37] KVM: s390: Add support for protected VMs Christian Borntraeger
2020-02-03 13:19 ` Christian Borntraeger [this message]
2020-02-03 15:42 ` [RFCv2 01/37] DOCUMENTATION: protvirt: Protected virtual machine introduction Cornelia Huck
2020-02-03 21:41 ` Christian Borntraeger
2020-02-04 9:19 ` Cornelia Huck
2020-02-04 9:32 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 02/37] s390/protvirt: introduce host side setup Christian Borntraeger
2020-02-03 17:12 ` Cornelia Huck
2020-02-03 22:03 ` Christian Borntraeger
2020-02-04 9:28 ` Cornelia Huck
2020-02-04 9:38 ` Christian Borntraeger
2020-02-04 9:49 ` Cornelia Huck
2020-02-04 8:40 ` Thomas Huth
2020-02-04 9:12 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 03/37] s390/protvirt: add ultravisor initialization Christian Borntraeger
2020-02-04 10:03 ` Thomas Huth
2020-02-04 10:23 ` Cornelia Huck
2020-02-04 11:22 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 04/37] mm:gup/writeback: add callbacks for inaccessible pages Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 05/37] s390/mm: provide memory management functions for protected KVM guests Christian Borntraeger
2020-02-04 10:57 ` Cornelia Huck
2020-02-04 11:48 ` Claudio Imbrenda
2020-02-04 11:56 ` Christian Borntraeger
2020-02-04 12:15 ` Cornelia Huck
2020-02-05 9:52 ` Janosch Frank
2020-02-03 13:19 ` [RFCv2 06/37] s390: add (non)secure page access exceptions handlers Christian Borntraeger
2020-02-04 10:37 ` Thomas Huth
2020-02-04 11:41 ` Claudio Imbrenda
2020-02-04 12:48 ` Thomas Huth
2020-02-04 13:08 ` Claudio Imbrenda
2020-02-04 13:22 ` Thomas Huth
2020-02-04 12:03 ` Christian Borntraeger
2020-02-04 11:18 ` Cornelia Huck
2020-02-04 12:04 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 07/37] KVM: s390: add new variants of UV CALL Christian Borntraeger
2020-02-04 12:11 ` Cornelia Huck
2020-02-04 12:30 ` Claudio Imbrenda
2020-02-04 12:34 ` Cornelia Huck
2020-02-04 13:33 ` Christian Borntraeger
2020-02-04 13:27 ` Thomas Huth
2020-02-04 13:55 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 08/37] KVM: s390: protvirt: Add initial lifecycle handling Christian Borntraeger
2020-02-04 12:13 ` David Hildenbrand
2020-02-04 12:34 ` Christian Borntraeger
2020-02-05 10:01 ` Janosch Frank
2020-02-04 16:27 ` Cornelia Huck
2020-02-04 21:13 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 09/37] KVM: s390: protvirt: Add KVM api documentation Christian Borntraeger
2020-02-04 20:19 ` Thomas Huth
2020-02-04 21:40 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 10/37] KVM: s390: protvirt: Secure memory is not mergeable Christian Borntraeger
2020-02-04 12:15 ` David Hildenbrand
2020-02-04 12:53 ` Christian Borntraeger
2020-02-04 12:54 ` David Hildenbrand
2020-02-04 13:04 ` [PATCH v2 " Christian Borntraeger
2020-02-04 13:05 ` David Hildenbrand
2020-02-03 13:19 ` [RFCv2 11/37] KVM: s390/mm: Make pages accessible before destroying the guest Christian Borntraeger
2020-02-04 20:52 ` Thomas Huth
2020-02-05 9:03 ` Christian Borntraeger
2020-02-05 10:35 ` Cornelia Huck
2020-02-05 18:29 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 12/37] KVM: s390: protvirt: Handle SE notification interceptions Christian Borntraeger
2020-02-04 12:16 ` David Hildenbrand
2020-02-04 12:23 ` Christian Borntraeger
2020-02-04 21:16 ` Thomas Huth
2020-02-04 21:46 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 13/37] KVM: s390: protvirt: Instruction emulation Christian Borntraeger
2020-02-04 12:20 ` David Hildenbrand
2020-02-04 12:29 ` Christian Borntraeger
2020-02-04 17:07 ` Cornelia Huck
2020-02-04 21:21 ` Thomas Huth
2020-02-03 13:19 ` [RFCv2 14/37] KVM: s390: protvirt: Add interruption injection controls Christian Borntraeger
2020-02-05 6:59 ` Thomas Huth
2020-02-05 8:46 ` Christian Borntraeger
2020-02-05 8:56 ` Michael Mueller
2020-02-05 8:54 ` Michael Mueller
2020-02-05 10:45 ` Cornelia Huck
2020-02-03 13:19 ` [RFCv2 15/37] KVM: s390: protvirt: Implement interruption injection Christian Borntraeger
2020-02-05 9:51 ` Thomas Huth
2020-02-05 10:48 ` Christian Borntraeger
2020-02-05 11:25 ` Cornelia Huck
2020-02-05 17:49 ` Christian Borntraeger
2020-02-06 8:21 ` Cornelia Huck
2020-02-05 17:56 ` Christian Borntraeger
2020-02-05 11:31 ` Cornelia Huck
2020-02-05 11:46 ` Michael Mueller
2020-02-05 12:11 ` Cornelia Huck
2020-02-05 12:26 ` Michael Mueller
2020-02-05 18:00 ` Christian Borntraeger
2020-02-06 8:23 ` Cornelia Huck
2020-02-05 15:30 ` Michael Mueller
2020-02-03 13:19 ` [RFCv2 16/37] KVM: s390: protvirt: Add SCLP interrupt handling Christian Borntraeger
2020-02-05 12:22 ` Cornelia Huck
2020-02-05 18:14 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 17/37] KVM: s390: protvirt: Add machine-check interruption injection controls Christian Borntraeger
2020-02-05 7:06 ` Thomas Huth
2020-02-03 13:19 ` [RFCv2 18/37] KVM: s390: protvirt: Implement machine-check interruption injection Christian Borntraeger
2020-02-05 7:10 ` Thomas Huth
2020-02-05 13:47 ` Cornelia Huck
2020-02-05 18:18 ` Christian Borntraeger
2020-02-06 8:25 ` Cornelia Huck
2020-02-06 9:01 ` Christian Borntraeger
2020-02-06 9:11 ` Cornelia Huck
2020-02-03 13:19 ` [RFCv2 19/37] KVM: s390: protvirt: Handle spec exception loops Christian Borntraeger
2020-02-05 13:50 ` Cornelia Huck
2020-02-05 18:21 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 20/37] KVM: s390: protvirt: Add new gprs location handling Christian Borntraeger
2020-02-05 11:18 ` Thomas Huth
2020-02-05 18:45 ` Christian Borntraeger
2020-02-05 13:52 ` Cornelia Huck
2020-02-03 13:19 ` [RFCv2 21/37] KVM: S390: protvirt: Introduce instruction data area bounce buffer Christian Borntraeger
2020-02-05 11:43 ` David Hildenbrand
2020-02-06 8:43 ` Christian Borntraeger
2020-02-05 12:02 ` Thomas Huth
2020-02-05 12:16 ` Janosch Frank
2020-02-05 17:00 ` Thomas Huth
2020-02-06 9:07 ` Christian Borntraeger
2020-02-06 9:18 ` Thomas Huth
2020-02-06 9:21 ` Christian Borntraeger
2020-02-06 9:20 ` Christian Borntraeger
2020-02-06 9:32 ` Janosch Frank
2020-02-06 9:29 ` David Hildenbrand
2020-02-06 9:39 ` [RFCv2.1] " Christian Borntraeger
2020-02-06 9:54 ` David Hildenbrand
2020-02-06 10:02 ` Christian Borntraeger
2020-02-06 10:08 ` David Hildenbrand
2020-02-06 10:10 ` Christian Borntraeger
2020-02-06 12:46 ` Christian Borntraeger
2020-02-06 10:32 ` Thomas Huth
2020-02-06 11:07 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 22/37] KVM: s390: protvirt: handle secure guest prefix pages Christian Borntraeger
2020-02-05 11:51 ` David Hildenbrand
2020-02-05 19:38 ` Christian Borntraeger
2020-02-05 11:52 ` David Hildenbrand
2020-02-05 19:39 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 23/37] KVM: s390/mm: handle guest unpin events Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 24/37] KVM: s390: protvirt: Write sthyi data to instruction data area Christian Borntraeger
2020-02-05 12:09 ` Thomas Huth
2020-02-05 18:52 ` Christian Borntraeger
2020-02-05 14:27 ` Cornelia Huck
2020-02-03 13:19 ` [RFCv2 25/37] KVM: s390: protvirt: STSI handling Christian Borntraeger
2020-02-05 12:13 ` Thomas Huth
2020-02-05 19:22 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 26/37] KVM: s390: protvirt: disallow one_reg Christian Borntraeger
2020-02-05 12:16 ` Thomas Huth
2020-02-05 19:25 ` Christian Borntraeger
2020-02-05 14:42 ` Cornelia Huck
2020-02-03 13:19 ` [RFCv2 27/37] KVM: s390: protvirt: Only sync fmt4 registers Christian Borntraeger
2020-02-04 17:15 ` Cornelia Huck
2020-02-04 22:08 ` Christian Borntraeger
2020-02-05 16:29 ` Cornelia Huck
2020-02-03 13:19 ` [RFCv2 28/37] KVM: s390: protvirt: Add program exception injection Christian Borntraeger
2020-02-05 16:38 ` Cornelia Huck
2020-02-05 19:31 ` Christian Borntraeger
2020-02-05 17:59 ` Thomas Huth
2020-02-05 19:32 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 29/37] DOCUMENTATION: protvirt: Diag 308 IPL Christian Borntraeger
2020-02-03 16:13 ` Cornelia Huck
2020-02-04 8:13 ` Christian Borntraeger
2020-02-04 9:35 ` Cornelia Huck
2020-02-03 13:19 ` [RFCv2 30/37] KVM: s390: protvirt: Add diag 308 subcode 8 - 10 handling Christian Borntraeger
2020-02-04 18:51 ` Cornelia Huck
2020-02-04 22:19 ` Christian Borntraeger
2020-02-05 18:21 ` Thomas Huth
2020-02-06 10:59 ` Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 31/37] KVM: s390: protvirt: UV calls diag308 0, 1 Christian Borntraeger
2020-02-03 13:19 ` [RFCv2 32/37] KVM: s390: protvirt: Report CPU state to Ultravisor Christian Borntraeger
2020-02-06 11:12 ` Thomas Huth
2020-02-06 11:17 ` Christian Borntraeger
2020-02-06 14:29 ` Cornelia Huck
2020-02-03 13:19 ` [RFCv2 33/37] KVM: s390: protvirt: Support cmd 5 operation state Christian Borntraeger
2020-02-06 11:21 ` Thomas Huth
2020-02-06 15:17 ` Cornelia Huck
2020-02-03 13:19 ` [RFCv2 34/37] KVM: s390: protvirt: Add UV debug trace Christian Borntraeger
2020-02-06 9:41 ` Cornelia Huck
2020-02-07 8:05 ` Christian Borntraeger
2020-02-07 8:27 ` Cornelia Huck
2020-02-14 8:32 ` Christian Borntraeger
2020-02-14 8:53 ` Cornelia Huck
2020-02-03 13:19 ` [RFCv2 35/37] KVM: s390: protvirt: Mask PSW interrupt bits for interception 104 and 112 Christian Borntraeger
2020-02-06 10:10 ` Cornelia Huck
2020-02-06 11:11 ` Christian Borntraeger
2020-02-06 12:03 ` Thomas Huth
2020-02-03 13:19 ` [RFCv2 36/37] KVM: s390: protvirt: do not inject interrupts after start Christian Borntraeger
2020-02-06 10:13 ` Cornelia Huck
2020-02-06 14:24 ` Christian Borntraeger
2020-02-06 12:03 ` Thomas Huth
2020-02-03 13:19 ` [RFCv2 37/37] KVM: s390: protvirt: Add UV cpu reset calls Christian Borntraeger
2020-02-05 18:27 ` Thomas Huth
2020-02-05 20:24 ` Christian Borntraeger
2020-02-06 10:45 ` Cornelia Huck
2020-02-06 14:27 ` Christian Borntraeger
2020-02-06 14:39 ` David Hildenbrand
2020-02-06 15:07 ` Thomas Huth
2020-02-03 13:23 ` [RFCv2 00/37] KVM: s390: Add support for protected VMs Cornelia Huck
2020-02-03 13:32 ` Christian Borntraeger
2020-02-03 14:42 ` Cornelia Huck
2020-02-05 11:34 ` David Hildenbrand
2020-02-05 11:38 ` Christian Borntraeger
2020-02-05 11:40 ` Cornelia Huck
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