Stephen Oberholtzer
2018-Oct-13 20:08 UTC
[Pkg-xen-devel] Bug#910961: xen-hypervisor-4.11-amd64: HVM domU fails to start when using PCI passthrough
Package: xen-hypervisor-4.11-amd64
Version: 4.11.1~pre.20180911.5acdd26fdc+dfsg-3
Severity: normal
Dear Maintainer,
HVM domUs that specify PCI passthrough will not start. The same configuration
file started under Xen 4.8.
The output I am receiving is as follows:
libxl: error: libxl_pci.c:1146:libxl__device_pci_reset: Domain 0:The kernel
doesn't support reset from sysfs for PCI device 0000:00:14.0
libxl: error: libxl_qmp.c:292:qmp_handle_error_response: Domain 31:received an
error message from QMP server: Binding of interrupt 0 failed: Permission denied
libxl: error: libxl_pci.c:1300:libxl__add_pcidevs: Domain
31:libxl_device_pci_add failed: -3
libxl: error: libxl_create.c:1519:domcreate_attach_devices: Domain 31:unable to
add pci devices
libxl: error: libxl_domain.c:1034:libxl__destroy_domid: Domain 31:Non-existant
domain
libxl: error: libxl_domain.c:993:domain_destroy_callback: Domain 31:Unable to
destroy guest
libxl: error: libxl_domain.c:920:domain_destroy_cb: Domain 31:Destruction of
domain failed
(There are three PCI devices I'm trying to pass through: 00:14.0,
01:00.[01], and 03:00.0. I tried each set individually, and got equivalent
results each time.)
With 'log_lvl=all guest_loglvl=all', all I get in xl dmesg is a bunch of
lines saying "HVM<domid> save:" for CPU, PIC, IOAPIC, etc.
Google gives me nothing. I can find a small number of (unanswered)
"Binding of interrupt 0 failed" messages, but none about
'Permission denied'.
However, it looks like the message may be incorrect, due to an mismatch between
qemu and libxen. Reading through the source code:
qemu: hw/xen/xen_pt.c line 874 logs the message.
874 error_setg_errno(errp, errno, "Binding of interrupt %u
failed",
875 e_intx);
That's using 'errno'. However, the failed call was to
xc_domain_bind_pt_pci_irq.
libxen: tools/libxc/xc_domain.c:1899, xc_domain_bind_pt_pci_irq forwards to
xc_domain_bind_pt_irq
libxen: tools/libxc/xc_domain.c:1827, xc_domain_bind_pt_irq forwards to
xc_domain_bind_pt_irq_int
libxen: tools/libxc/xc_domain.c:1783, xc_domain_bind_pt_irq_int
If an invalid argument is passed, this function returns -1 and sets errno to
EINVAL, matching what qemu is expecting.
If pre-validation passes, the request is forwarded to do_domctl.
lixben: xen/common/domctl.c:380, do_domctl
This function doesn't seem to set errno. Instead, it returns (-ETHING).
This means that, if the request is handled by do_domctl, errno is unchanged, and
so the "Permission denied" message may be
from an EPERM left in errno from an earlier operation.
-- System Information:
Debian Release: buster/sid
APT prefers testing
APT policy: (900, 'testing'), (400, 'unstable')
Architecture: amd64 (x86_64)
Kernel: Linux 4.18.6 (SMP w/12 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8),
LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
xen-hypervisor-4.11-amd64 depends on no packages.
Versions of packages xen-hypervisor-4.11-amd64 recommends:
ii xen-hypervisor-common 4.11.1~pre.20180911.5acdd26fdc+dfsg-1~exp1
ii xen-utils-4.11 4.11.1~pre.20180911.5acdd26fdc+dfsg-3
xen-hypervisor-4.11-amd64 suggests no packages.
-- no debconf information
-- System Information:
Debian Release: buster/sid
APT prefers testing
APT policy: (900, 'testing'), (400, 'unstable')
Architecture: amd64 (x86_64)
Kernel: Linux 4.18.6 (SMP w/12 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8),
LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
xen-hypervisor-4.11-amd64 depends on no packages.
Versions of packages xen-hypervisor-4.11-amd64 recommends:
ii xen-hypervisor-common 4.11.1~pre.20180911.5acdd26fdc+dfsg-1~exp1
ii xen-utils-4.11 4.11.1~pre.20180911.5acdd26fdc+dfsg-3
xen-hypervisor-4.11-amd64 suggests no packages.
-- no debconf information