From: Matthew Rosato <mjrosato@linux.ibm.com>
To: alex.williamson@redhat.com, pmorel@linux.ibm.com, schnelle@linux.ibm.com
Cc: david@redhat.com, cohuck@redhat.com, qemu-devel@nongnu.org,
pasic@linux.ibm.com, borntraeger@de.ibm.com,
qemu-s390x@nongnu.org, rth@twiddle.net
Subject: [RFC PATCH] s390x/pci: Enforce PCI_COMMAND_MEMORY for vfio-pci
Date: Thu, 23 Jul 2020 11:13:56 -0400 [thread overview]
Message-ID: <1595517236-17823-2-git-send-email-mjrosato@linux.ibm.com> (raw)
In-Reply-To: <1595517236-17823-1-git-send-email-mjrosato@linux.ibm.com>
After kernel commit abafbc55 'vfio-pci: Invalidate mmaps and
block MMIO access on disabled memory', I'm seeing qemu errors
on s390x as vfio-pci devices attempt to read bar 0 because
PCI_COMMAND_MEMORY is not reliably set. Ensure the value
stays ON while the device is in-use.
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
---
hw/s390x/s390-pci-inst.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c
index 2f7a7d7..74b8796 100644
--- a/hw/s390x/s390-pci-inst.c
+++ b/hw/s390x/s390-pci-inst.c
@@ -555,6 +555,16 @@ int pcistg_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra)
}
/* len = 1,2,4 so we do not need to test */
zpci_endian_swap(&data, len);
+
+ /*
+ * vfio-pci requires PCI_COMMAND_MEMORY. Ensure that it
+ * stays on for an active device.
+ */
+ if ((pbdev->fh & FH_SHM_VFIO) && (offset == PCI_COMMAND) &&
+ (len == 2) && (data != 0)) {
+ data |= PCI_COMMAND_MEMORY;
+ }
+
pci_host_config_write_common(pbdev->pdev, offset,
pci_config_size(pbdev->pdev),
data, len);
--
1.8.3.1
next prev parent reply other threads:[~2020-07-23 15:16 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-23 15:13 [RFC PATCH] s390x/pci: vfio-pci breakage with disabled mem enforcement Matthew Rosato
2020-07-23 15:13 ` Matthew Rosato [this message]
2020-07-23 16:29 ` Alex Williamson
2020-07-23 18:12 ` Matthew Rosato
2020-07-27 15:40 ` Pierre Morel
2020-07-27 16:37 ` Matthew Rosato
2020-07-27 16:47 ` Alex Williamson
2020-07-28 9:33 ` Niklas Schnelle
2020-07-28 12:52 ` Alex Williamson
2020-07-28 14:13 ` Niklas Schnelle
2020-07-28 8:59 ` Niklas Schnelle
2020-07-24 9:46 ` Niklas Schnelle
2020-07-24 9:53 ` Niklas Schnelle
2020-07-24 14:15 ` Niklas Schnelle
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=1595517236-17823-2-git-send-email-mjrosato@linux.ibm.com \
--to=mjrosato@linux.ibm.com \
--cc=alex.williamson@redhat.com \
--cc=borntraeger@de.ibm.com \
--cc=cohuck@redhat.com \
--cc=david@redhat.com \
--cc=pasic@linux.ibm.com \
--cc=pmorel@linux.ibm.com \
--cc=qemu-devel@nongnu.org \
--cc=qemu-s390x@nongnu.org \
--cc=rth@twiddle.net \
--cc=schnelle@linux.ibm.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).