January 2026 - Devel - libvirt List Archives

[PATCH] build: add detection of xdrproc_t arguments count
by Roman Bogorodskiy 04 Feb '26

04 Feb '26

According to 9fa3a8ab6fd82ad2f5a14b490696085061418718, macOS insists on passing 3 arguments for xdrproc_t. Passing 3 arguments was a good common ground, but since recently[1] FreeBSD only accepts 2 arguments. Add a meson.build check whether 3 arguments are accepted, and add macros which passes either 2 or 3 arguments to xdrproc_t based on the result of this check. 1: https://cgit.freebsd.org/src/commit/?id=ac5a19ec6989675c8ec6c3ca245dba243d1… Signed-off-by: Roman Bogorodskiy <bogorodskiy(a)gmail.com> --- meson.build | 19 +++++++++++++++++++ scripts/rpcgen/tests/test_demo.c | 12 +++++++++--- src/rpc/virnetmessage.c | 10 ++++++++-- 3 files changed, 36 insertions(+), 5 deletions(-) diff --git a/meson.build b/meson.build index 964d1fa4e1..4a4f89c1cb 100644 --- a/meson.build +++ b/meson.build @@ -893,6 +893,25 @@ else xdr_dep = dependency('', required: false) endif +if xdr_dep.found() + xdrproc_3arg_code = ''' + #include <rpc/xdr.h> + + bool_t test_filter(XDR *xdr, void *data, unsigned int opaque_flags) { + return TRUE; + } + + int main() { + XDR xdr; + xdrproc_t filter = (xdrproc_t)&test_filter; + (*filter)(&xdr, NULL, 0); + return 0; + } + ''' + if cc.compiles(xdrproc_3arg_code, dependencies: xdr_dep) + conf.set('XDRPROC_T_3ARGS', 1) + endif +endif # generic build dependencies diff --git a/scripts/rpcgen/tests/test_demo.c b/scripts/rpcgen/tests/test_demo.c index e6ba7ddbc5..82eda89592 100644 --- a/scripts/rpcgen/tests/test_demo.c +++ b/scripts/rpcgen/tests/test_demo.c @@ -8,6 +8,12 @@ # define xdr_uint64_t xdr_u_int64_t #endif +#if defined(XDRPROC_T_3ARGS) +# define XDRPROC(proc, xdr, data) (proc(&xdr, data, 0)) +#else +# define XDRPROC(proc, xdr, data) (proc(&xdr, data)) +#endif + #include "demo.h" #include "demo.c" @@ -27,7 +33,7 @@ static void test_xdr(xdrproc_t proc, void *vorig, void *vnew, const char *testna /* Step 1: serialize the vorig and compare to the data in test .bin files */ xdrmem_create(&xdr, buf, buflen, XDR_ENCODE); - ret = !!proc(&xdr, vorig, 0); + ret = !!XDRPROC(proc, xdr, vorig); g_assert_cmpint(ret, ==, !fail); if (fail) @@ -54,7 +60,7 @@ static void test_xdr(xdrproc_t proc, void *vorig, void *vnew, const char *testna /* Step 2: de-serialize the state to create a new object */ xdrmem_create(&xdr, buf, buflen, XDR_DECODE); - ret = !!proc(&xdr, vnew, 0); + ret = !!XDRPROC(proc, xdr, vnew); g_assert_cmpint(ret, ==, true); actlen = xdr_getpos(&xdr); @@ -68,7 +74,7 @@ static void test_xdr(xdrproc_t proc, void *vorig, void *vnew, const char *testna xdrmem_create(&xdr, buf, buflen, XDR_ENCODE); - ret = !!proc(&xdr, vnew, 0); + ret = !!XDRPROC(proc, xdr, vnew); g_assert_cmpint(ret, ==, true); actlen = xdr_getpos(&xdr); diff --git a/src/rpc/virnetmessage.c b/src/rpc/virnetmessage.c index af0f9cb30b..e66df5c9e2 100644 --- a/src/rpc/virnetmessage.c +++ b/src/rpc/virnetmessage.c @@ -34,6 +34,12 @@ VIR_LOG_INIT("rpc.netmessage"); +#if defined(XDRPROC_T_3ARGS) +# define XDRPROC_FILTER(filter, xdr, data) ((*filter)(&xdr, data, 0)) +#else +# define XDRPROC_FILTER(filter, xdr, data) ((*filter)(&xdr, data)) +#endif + virNetMessage *virNetMessageNew(bool tracked) { virNetMessage *msg; @@ -367,7 +373,7 @@ int virNetMessageEncodePayload(virNetMessage *msg, msg->bufferLength - msg->bufferOffset, XDR_ENCODE); /* Try to encode the payload. If the buffer is too small increase it. */ - while (!(*filter)(&xdr, data, 0)) { + while (!XDRPROC_FILTER(*filter, xdr, data)) { unsigned int newlen = msg->bufferLength - VIR_NET_MESSAGE_LEN_MAX; newlen *= 2; @@ -424,7 +430,7 @@ int virNetMessageDecodePayload(virNetMessage *msg, xdrmem_create(&xdr, msg->buffer + msg->bufferOffset, msg->bufferLength - msg->bufferOffset, XDR_DECODE); - if (!(*filter)(&xdr, data, 0)) { + if (!XDRPROC_FILTER(*filter, xdr, data)) { virReportError(VIR_ERR_RPC, "%s", _("Unable to decode message payload")); goto error; } -- 2.52.0

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[RFC PATCH v4 0/7] riscv: add initial sdext support
by Chao Liu 03 Feb '26

03 Feb '26

Hi, Per Daniel's review feedback, this v4 series is based on Alistair's riscv-to-apply.next branch [3]. It depends on patches 1-5 of Max Chou's "Add Zvfbfa extension support" v2 series (not included; apply them first) [2]. It is based on RISC-V Debug Specification 1.0 [1]. It introduces the sdext/sdtrig config bits, DCSR/DPC/DSCRATCH state, Debug Mode enter/leave helpers, DRET, EBREAK entry, single-step, and trigger action=debug mode. To reduce review load, this series focuses on the Sdext features first. The Debug Module (DM) and related flows will follow in a later series. Changes in v4: - Fixed linux-user build errors: moved debug_mode/dcsr/dpc/dscratch fields inside #ifndef CONFIG_USER_ONLY block in cpu.h, and wrapped all code using these fields with proper guards. (Daniel) - Updated dependency from single patch (patch 5 only) to patches 1-5 of Max Chou's "Add Zvfbfa extension support" v2 series to avoid compilation errors. Changes in v3: - Rebase onto Alistair's riscv-to-apply.next branch. - Depend on Max Chou's patch "target/riscv: Use the tb->cs_bqse as the extend tb flags." (not included; apply it first) [2]. - Patch 2: default sdext to false in riscv_cpu_extensions[]. Changes in v2: - Drop the RHCT expected AML update from this series. - Replace the split sdext/sdtrig config bits patch with deprecating the 'debug' CPU property. - Rebase and update patch subjects to target/riscv prefix. Changes in v1: - Debug Mode entry/exit updates DCSR/DPC and restores execution via DRET. - EBREAK honors DCSR ebreak bits and enters Debug Mode when enabled. - Single-step uses DCSR.STEP with a TB flag and a helper at TB exit. It references Max Chou's patch "target/riscv: Use the tb->cs_bqse as the extend tb flags." [2]. - Sdtrig supports action=debug mode for mcontrol/mcontrol6 and reports inst-count triggers in tinfo. Differences vs Debug Spec (known gaps): - No Debug Module (no DMI, dmcontrol/dmstatus, haltreq/resumereq). - No debug ROM, program buffer, abstract commands, or SBA. - Resume is modeled by leaving Debug Mode at cpu_exec_enter. - Step/exception ordering is simplified: if the stepped instruction traps, the normal exception is taken and Debug Mode is not forced. - Several DCSR fields are not fully modeled (stopcount/stoptime, etc). Roadmap (next stage, DM focus): 1) Add a DM core with DMI access and hart state tracking. 2) Implement halt/resume handshake and move Debug Mode transitions under DM control. 3) Add debug ROM, program buffer, and abstract commands for GPR/CSR and memory access. 4) Add SBA if required by tooling. 5) Tighten ordering rules for step/exception/trigger priorities. References: [1] https://github.com/riscv/riscv-debug-spec/releases/tag/1.0 [2] https://lore.kernel.org/qemu-devel/20260108132631.9429-1-max.chou@sifive.co… [3] https://github.com/alistair23/qemu/tree/riscv-to-apply.next Thanks, Chao Chao Liu (6): target/riscv: add sdext debug CSRs state target/riscv: add sdext Debug Mode helpers target/riscv: add dret instruction target/riscv: add sdext enter Debug Mode on ebreak target/riscv: add sdext single-step support target/riscv: add sdtrig trigger action=debug mode Daniel Henrique Barboza (1): target/riscv: deprecate 'debug' CPU property docs/about/deprecated.rst | 7 + include/exec/translation-block.h | 4 +- target/riscv/cpu.c | 62 ++++++++- target/riscv/cpu.h | 9 ++ target/riscv/cpu_bits.h | 33 +++++ target/riscv/cpu_cfg_fields.h.inc | 3 +- target/riscv/cpu_helper.c | 90 ++++++++++++ target/riscv/csr.c | 128 +++++++++++++++++- target/riscv/debug.c | 58 +++++++- target/riscv/helper.h | 3 + target/riscv/insn32.decode | 1 + .../riscv/insn_trans/trans_privileged.c.inc | 24 ++++ target/riscv/machine.c | 44 ++++-- target/riscv/op_helper.c | 70 ++++++++++ target/riscv/tcg/tcg-cpu.c | 21 ++- target/riscv/translate.c | 16 ++- 16 files changed, 548 insertions(+), 25 deletions(-) -- 2.52.0

2 15

Qemu pause-before-switchover and libvirt live migration
by Rogério Vinhal Nunes 03 Feb '26

03 Feb '26

Hello, I’m looking into the libvirt hooks that are available to make use of during a live migration, but there's only hooks on migration begin and migration end. On qemu directly I’m able to use pause-before-switchover migration capability to run a custom operation just before it moves to the destination, but within libvirt it seems that while this is leveraged internally, it’s not currently exposed to the client in a way I can use. Does anyone have any suggestions on how I could expose this to the client in a generic and sensible way? Thanks, Rogerio

3 11

[PATCH v6 0/7] qemu: Implement support for iommufd
by Nathan Chen 03 Feb '26

03 Feb '26

Hi, This is a follow up to the fifth patch series [0] for using iommufd to propagate DMA mappings to the kernel for VM-assigned host devices in a qemu VM. We add a new 'iommufd' attribute for hostdev devices to be associated with the iommufd object. For instance, specifying the iommufd object and associated hostdev in a VM definition: <devices> ... <hostdev mode='subsystem' type='pci' managed='no'> <driver iommufd='yes'/> <source> <address domain='0x0009' bus='0x01' slot='0x00' function='0x0'/> </source> <address type='pci' domain='0x0000' bus='0x15' slot='0x00' function='0x0'/> </hostdev> <hostdev mode='subsystem' type='pci' managed='no'> <driver iommufd='yes'/> <source> <address domain='0x0019' bus='0x01' slot='0x00' function='0x0'/> </source> <address type='pci' domain='0x0000' bus='0x16' slot='0x00' function='0x0'/> </hostdev> ... </devices> This would get translated to a qemu command line with the arguments below. Note that libvirt will open the /dev/iommu and VFIO cdev, passing the associated fd number to qemu: -object '{"qom-type":"iommufd","id":"iommufd0","fd":"24"}' \ -device '{"driver":"vfio-pci","host":"0009:01:00.0","id":"hostdev0","iommufd":"iommufd0","fd":"22","bus":"pci.21","addr":"0x0"}' \ -device '{"driver":"vfio-pci","host":"0019:01:00.0","id":"hostdev1","iommufd":"iommufd0","fd":"25","bus":"pci.22","addr":"0x0"}' \ Changes from v5: - Updated documentation to point to 12.1.0 (QEMU and KVM only) - Move define and VIR_LOG_INIT out of #ifdef __linux__ block in viriommufd.h - Remove unneeded virPCIDeviceFree() from AppArmorSetSecurityHostdevLabel - Always error out if per-process accounting failed Changes from v4: - Move qemuProcessOpenVfioFds() to qemu_process.h in patch 4/7 - Add `linux/iommufd.h` into headers list in the meson.build file - Correct viriommufd.c pre-processor definition indentations - Restore call to virIOMMUFDSetRLimitMode() in patch 5/7 - Fix indentations for various print function calls - Move the qemuProcessOpenVfioFds() call to qemuProcessPrepareHost() - Make qemuProcessOpenVfioFds() static - Remove unnecessary formatting and comment in virPCIDeviceGetVfioPath() - Clean up namespace and cgroup changes with conditional check for iommufd - Remove virIOMMUFDSupported() - Fix seclabel return logic - In Apparmor seclabel logic, use g_autoptr for virPCIDevice pointer Changes from v3: - Resolved issue from v2 where stale FD from previous VM boot was in use - Remove second approach for retrieving VFIO device path in virPCIDeviceGetVfioPath() - Resolve broken build of libvirt on non-Linux platforms - Conditionally define iommufd headers and use system headers where possible - Add non-fatal handling + warning print for EPERM for the IOMMU_OPTION_RLIMIT_MODE ioctl - Replace references to /dev/iommu with VIR_IOMMU_DEV_PATH - Implement virIOMMUFDSupported(void) to check for existence of /dev/iommu on host - Include tests for multiple hostdevs Changes from v2: - Set per-process memory accounting mode for iommufd - Separated out formatting of iommufd object from qemuBuildHostdevCommandLine - Placed hostdev private data implementation in a separate commit - Allocate hostdev private data unconditionally - Compare FDs against -1 - Integrated callback function in virQEMUDriverPrivateDataCallbacks for qemuDomainHostdevPrivateNew - Dropped qemuProcessCloseVfioFds - Addressed other feedback from v2 (formatting, includes, etc.) - Revised seclabel logic to be device-specific for AppArmor and to allow paths for SELinux/DAC This series is on Github: https://github.com/NathanChenNVIDIA/libvirt/commits/iommufd-v6-01-26 Thanks, Nathan [0] https://lists.libvirt.org/archives/list/devel@lists.libvirt.org/thread/GKSD… Nathan Chen (7): qemu: Implement support for associating iommufd to hostdev qemu: Introduce privateData for hostdevs qemu: Support per-process memory accounting for iommufd qemu: open VFIO FDs from libvirt backend qemu: open iommufd FD from libvirt backend qemu: Update Cgroup, namespace, and seclabel for iommufd tests: qemuxmlconfdata: provide iommufd sample XML and CLI args docs/formatdomain.rst | 6 + meson.build | 1 + po/POTFILES | 1 + src/bhyve/bhyve_parse_command.c | 2 +- src/conf/device_conf.c | 11 ++ src/conf/device_conf.h | 1 + src/conf/domain_conf.c | 13 +- src/conf/domain_conf.h | 5 +- src/conf/schemas/basictypes.rng | 5 + src/libvirt_private.syms | 4 + src/libxl/xen_common.c | 2 +- src/libxl/xen_xl.c | 2 +- src/lxc/lxc_native.c | 2 +- src/qemu/qemu_cgroup.c | 3 + src/qemu/qemu_command.c | 76 +++++++++++ src/qemu/qemu_domain.c | 41 ++++++ src/qemu/qemu_domain.h | 17 +++ src/qemu/qemu_namespace.c | 3 + src/qemu/qemu_process.c | 121 ++++++++++++++++++ src/security/security_apparmor.c | 28 ++-- src/security/security_dac.c | 49 +++++-- src/security/security_selinux.c | 47 +++++-- src/security/virt-aa-helper.c | 33 ++++- src/util/meson.build | 1 + src/util/viriommufd.c | 111 ++++++++++++++++ src/util/viriommufd.h | 25 ++++ src/util/virpci.c | 39 ++++++ src/util/virpci.h | 2 + src/vbox/vbox_common.c | 2 +- .../iommufd-q35.x86_64-latest.args | 41 ++++++ .../iommufd-q35.x86_64-latest.xml | 60 +++++++++ tests/qemuxmlconfdata/iommufd-q35.xml | 38 ++++++ ...fd-virt-pci-bus-single.aarch64-latest.args | 32 +++++ ...ufd-virt-pci-bus-single.aarch64-latest.xml | 31 +++++ .../iommufd-virt-pci-bus-single.xml | 22 ++++ .../iommufd-virt.aarch64-latest.args | 36 ++++++ .../iommufd-virt.aarch64-latest.xml | 53 ++++++++ tests/qemuxmlconfdata/iommufd-virt.xml | 29 +++++ .../iommufd.x86_64-latest.args | 35 +++++ .../qemuxmlconfdata/iommufd.x86_64-latest.xml | 38 ++++++ tests/qemuxmlconfdata/iommufd.xml | 30 +++++ tests/qemuxmlconftest.c | 34 +++++ tests/virhostdevtest.c | 2 +- 43 files changed, 1090 insertions(+), 44 deletions(-) create mode 100644 src/util/viriommufd.c create mode 100644 src/util/viriommufd.h create mode 100644 tests/qemuxmlconfdata/iommufd-q35.x86_64-latest.args create mode 100644 tests/qemuxmlconfdata/iommufd-q35.x86_64-latest.xml create mode 100644 tests/qemuxmlconfdata/iommufd-q35.xml create mode 100644 tests/qemuxmlconfdata/iommufd-virt-pci-bus-single.aarch64-latest.args create mode 100644 tests/qemuxmlconfdata/iommufd-virt-pci-bus-single.aarch64-latest.xml create mode 100644 tests/qemuxmlconfdata/iommufd-virt-pci-bus-single.xml create mode 100644 tests/qemuxmlconfdata/iommufd-virt.aarch64-latest.args create mode 100644 tests/qemuxmlconfdata/iommufd-virt.aarch64-latest.xml create mode 100644 tests/qemuxmlconfdata/iommufd-virt.xml create mode 100644 tests/qemuxmlconfdata/iommufd.x86_64-latest.args create mode 100644 tests/qemuxmlconfdata/iommufd.x86_64-latest.xml create mode 100644 tests/qemuxmlconfdata/iommufd.xml -- 2.43.0

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[PATCH 0/2] target/arm: Deprecate '-cpu any'
by Philippe Mathieu-Daudé 02 Feb '26

02 Feb '26

Arm '-cpu any' is aliased to '-cpu max' since more than 5 years. Deprecate the former in preparation of removal. Philippe Mathieu-Daudé (2): target/arm: Remove dead code target/arm: Deprecate '-cpu any' (remplaced by '-cpu max') docs/about/deprecated.rst | 8 ++++++++ target/arm/cpu.c | 1 + target/arm/tcg/cpu32.c | 3 --- 3 files changed, 9 insertions(+), 3 deletions(-) -- 2.52.0

2 3

[PATCH v7 0/2] qemu: Support accelerated vSMMUs
by Nathan Chen 31 Jan '26

31 Jan '26

Hi, This is a follow up to the sixth RFC patchset [0] for supporting multiple accelerated vSMMU instances. Support for user-creatable accelerated SMMUv3 in QEMU has been applied to target-arm.next [1]. For instance, specifying hostdevs associated with multiple accelerated SMMUs, configured to be routed to pcie-expander-bus controllers in a way where VFIO device to SMMUv3 associations are matched with the host: <devices> ... <controller type='pci' index='1' model='pcie-expander-bus'> <model name='pxb-pcie'/> <target busNr='252'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0'/> </controller> <controller type='pci' index='2' model='pcie-expander-bus'> <model name='pxb-pcie'/> <target busNr='248'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </controller> ... <controller type='pci' index='21' model='pcie-root-port'> <model name='pcie-root-port'/> <target chassis='21' port='0x0'/> <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/> </controller> <controller type='pci' index='22' model='pcie-root-port'> <model name='pcie-root-port'/> <target chassis='22' port='0xa8'/> <address type='pci' domain='0x0000' bus='0x02' slot='0x00' function='0x0'/> </controller> ... <hostdev mode='subsystem' type='pci' managed='no'> <source> <address domain='0x0009' bus='0x01' slot='0x00' function='0x0'/> </source> <vpasidCapOffset>0xff8</vpasidCapOffset> <address type='pci' domain='0x0000' bus='0x15' slot='0x00' function='0x0'/> </hostdev> <hostdev mode='subsystem' type='pci' managed='no'> <source> <address domain='0x0019' bus='0x01' slot='0x00' function='0x0'/> </source> <vpasidCapOffset>0xff8</vpasidCapOffset> <address type='pci' domain='0x0000' bus='0x16' slot='0x00' function='0x0'/> </hostdev> <iommu model='smmuv3'> <driver parentIdx='1' accel='on' ats='on' ril='off' ssidSize='20' oas='44'/> </iommu> <iommu model='smmuv3'> <driver parentIdx='2' accel='on' ats='on' ril='off' ssidSize='20' oas='44'/> </iommu> </devices> This would get translated to a qemu command line with the arguments below: -device '{"driver":"pxb-pcie","bus_nr":252,"id":"pci.1","bus":"pcie.0","addr":"0x1"}' \ -device '{"driver":"pxb-pcie","bus_nr":248,"id":"pci.2","bus":"pcie.0","addr":"0x2"}' \ -device '{"driver":"pcie-root-port","port":0,"chassis":21,"id":"pci.21","bus":"pci.1","addr":"0x0"}' \ -device '{"driver":"pcie-root-port","port":168,"chassis":22,"id":"pci.22","bus":"pci.2","addr":"0x0"}' \ -device '{"driver":"arm-smmuv3","primary-bus":"pci.1","id":"iommu0","accel":true,"ats":true,"ril":false,"ssidsize":20,"oas":44}' \ -device '{"driver":"arm-smmuv3","primary-bus":"pci.2","id":"iommu1","accel":true,"ats":true,"ril":false,"ssidsize":20,"oas":44}' \ -device '{"driver":"vfio-pci","host":"0009:01:00.0","id":"hostdev0","x-vpasid-cap-offset":4088,"bus":"pci.21","addr":"0x0"}' \ -device '{"driver":"vfio-pci","host":"0019:01:00.0","id":"hostdev1","x-vpasid-cap-offset":4088,"bus":"pci.22","addr":"0x0"}' \ This series is on Github: https://github.com/NathanChenNVIDIA/libvirt/tree/smmuv3-accel-01-26-v7/ Thanks, Nathan Changes from v6: - Remove smmuv3 'pasid' attribute - Add smmuv3 'ssidsize' attribute - Add support for 'vpasidCapOffset' element - Modify logic for building accel smmuv3 qemu command line to omit ATS, RIL, accel flags when not needed (enabled/disabled by default in QEMU SMMUv3) [0] https://lists.libvirt.org/archives/list/devel@lists.libvirt.org/thread/VRSS… [1] https://lore.kernel.org/qemu-devel/20260126104342.253965-1-skolothumtho@nvi… Nathan Chen (2): qemu: Add support for HW-accelerated nested SMMUv3 tests: qemuxmlconfdata: provide HW-accel smmuv3 sample XML and CLI args docs/formatdomain.rst | 36 +++++++ src/conf/domain_conf.c | 101 +++++++++++++++++- src/conf/domain_conf.h | 6 ++ src/conf/domain_validate.c | 36 ++++++- src/conf/schemas/domaincommon.rng | 32 ++++++ src/qemu/qemu_command.c | 23 ++++ src/util/virpci.h | 4 + ...u-smmuv3-pci-bus-accel.aarch64-latest.args | 38 +++++++ ...mu-smmuv3-pci-bus-accel.aarch64-latest.xml | 64 +++++++++++ .../iommu-smmuv3-pci-bus-accel.xml | 54 ++++++++++ tests/qemuxmlconftest.c | 1 + 11 files changed, 390 insertions(+), 5 deletions(-) create mode 100644 tests/qemuxmlconfdata/iommu-smmuv3-pci-bus-accel.aarch64-latest.args create mode 100644 tests/qemuxmlconfdata/iommu-smmuv3-pci-bus-accel.aarch64-latest.xml create mode 100644 tests/qemuxmlconfdata/iommu-smmuv3-pci-bus-accel.xml -- 2.43.0

1 2

[PATCH v5 0/7] qemu: Implement support for iommufd
by Nathan Chen 31 Jan '26

31 Jan '26

Hi, This is a follow up to the fourth patch series [0] for using iommufd to propagate DMA mappings to the kernel for VM-assigned host devices in a qemu VM. We add a new 'iommufd' attribute for hostdev devices to be associated with the iommufd object. For instance, specifying the iommufd object and associated hostdev in a VM definition: <devices> ... <hostdev mode='subsystem' type='pci' managed='no'> <driver iommufd='yes'/> <source> <address domain='0x0009' bus='0x01' slot='0x00' function='0x0'/> </source> <address type='pci' domain='0x0000' bus='0x15' slot='0x00' function='0x0'/> </hostdev> <hostdev mode='subsystem' type='pci' managed='no'> <driver iommufd='yes'/> <source> <address domain='0x0019' bus='0x01' slot='0x00' function='0x0'/> </source> <address type='pci' domain='0x0000' bus='0x16' slot='0x00' function='0x0'/> </hostdev> ... </devices> This would get translated to a qemu command line with the arguments below. Note that libvirt will open the /dev/iommu and VFIO cdev, passing the associated fd number to qemu: -object '{"qom-type":"iommufd","id":"iommufd0","fd":"24"}' \ -device '{"driver":"vfio-pci","host":"0009:01:00.0","id":"hostdev0","iommufd":"iommufd0","fd":"22","bus":"pci.21","addr":"0x0"}' \ -device '{"driver":"vfio-pci","host":"0019:01:00.0","id":"hostdev1","iommufd":"iommufd0","fd":"25","bus":"pci.22","addr":"0x0"}' \ Changes from v4: - Move qemuProcessOpenVfioFds() to qemu_process.h in patch 4/7 - Add `linux/iommufd.h` into headers list in the meson.build file - Correct viriommufd.c pre-processor definition indentations - Restore call to virIOMMUFDSetRLimitMode() in patch 5/7 - Fix indentations for various print function calls - Move the qemuProcessOpenVfioFds() call to qemuProcessPrepareHost() - Make qemuProcessOpenVfioFds() static - Remove unnecessary formatting and comment in virPCIDeviceGetVfioPath() - Clean up namespace and cgroup changes with conditional check for iommufd - Remove virIOMMUFDSupported() - Fix seclabel return logic - In Apparmor seclabel logic, use g_autoptr for virPCIDevice pointer Changes from v3: - Resolved issue from v2 where stale FD from previous VM boot was in use - Remove second approach for retrieving VFIO device path in virPCIDeviceGetVfioPath() - Resolve broken build of libvirt on non-Linux platforms - Conditionally define iommufd headers and use system headers where possible - Add non-fatal handling + warning print for EPERM for the IOMMU_OPTION_RLIMIT_MODE ioctl - Replace references to /dev/iommu with VIR_IOMMU_DEV_PATH - Implement virIOMMUFDSupported(void) to check for existence of /dev/iommu on host - Include tests for multiple hostdevs Changes from v2: - Set per-process memory accounting mode for iommufd - Separated out formatting of iommufd object from qemuBuildHostdevCommandLine - Placed hostdev private data implementation in a separate commit - Allocate hostdev private data unconditionally - Compare FDs against -1 - Integrated callback function in virQEMUDriverPrivateDataCallbacks for qemuDomainHostdevPrivateNew - Dropped qemuProcessCloseVfioFds - Addressed other feedback from v2 (formatting, includes, etc.) - Revised seclabel logic to be device-specific for AppArmor and to allow paths for SELinux/DAC This series is on Github: https://github.com/NathanChenNVIDIA/libvirt/commits/iommufd-v5-01-26 Thanks, Nathan [0] https://lists.libvirt.org/archives/list/devel@lists.libvirt.org/thread/4BEU… Nathan Chen (7): qemu: Implement support for associating iommufd to hostdev qemu: Introduce privateData for hostdevs qemu: Support per-process memory accounting for iommufd qemu: open VFIO FDs from libvirt backend qemu: open iommufd FD from libvirt backend qemu: Update Cgroup, namespace, and seclabel for iommufd tests: qemuxmlconfdata: provide iommufd sample XML and CLI args docs/formatdomain.rst | 7 + meson.build | 1 + po/POTFILES | 1 + src/bhyve/bhyve_parse_command.c | 2 +- src/conf/device_conf.c | 11 ++ src/conf/device_conf.h | 1 + src/conf/domain_conf.c | 13 +- src/conf/domain_conf.h | 5 +- src/conf/schemas/basictypes.rng | 5 + src/libvirt_private.syms | 4 + src/libxl/xen_common.c | 2 +- src/libxl/xen_xl.c | 2 +- src/lxc/lxc_native.c | 2 +- src/qemu/qemu_cgroup.c | 3 + src/qemu/qemu_command.c | 76 +++++++++++ src/qemu/qemu_domain.c | 41 ++++++ src/qemu/qemu_domain.h | 17 +++ src/qemu/qemu_namespace.c | 3 + src/qemu/qemu_process.c | 121 ++++++++++++++++++ src/security/security_apparmor.c | 31 +++-- src/security/security_dac.c | 49 +++++-- src/security/security_selinux.c | 47 +++++-- src/security/virt-aa-helper.c | 33 ++++- src/util/meson.build | 1 + src/util/viriommufd.c | 111 ++++++++++++++++ src/util/viriommufd.h | 25 ++++ src/util/virpci.c | 39 ++++++ src/util/virpci.h | 2 + src/vbox/vbox_common.c | 2 +- .../iommufd-q35.x86_64-latest.args | 41 ++++++ .../iommufd-q35.x86_64-latest.xml | 60 +++++++++ tests/qemuxmlconfdata/iommufd-q35.xml | 38 ++++++ ...fd-virt-pci-bus-single.aarch64-latest.args | 32 +++++ ...ufd-virt-pci-bus-single.aarch64-latest.xml | 31 +++++ .../iommufd-virt-pci-bus-single.xml | 22 ++++ .../iommufd-virt.aarch64-latest.args | 36 ++++++ .../iommufd-virt.aarch64-latest.xml | 53 ++++++++ tests/qemuxmlconfdata/iommufd-virt.xml | 29 +++++ .../iommufd.x86_64-latest.args | 35 +++++ .../qemuxmlconfdata/iommufd.x86_64-latest.xml | 38 ++++++ tests/qemuxmlconfdata/iommufd.xml | 30 +++++ tests/qemuxmlconftest.c | 34 +++++ tests/virhostdevtest.c | 2 +- 43 files changed, 1093 insertions(+), 45 deletions(-) create mode 100644 src/util/viriommufd.c create mode 100644 src/util/viriommufd.h create mode 100644 tests/qemuxmlconfdata/iommufd-q35.x86_64-latest.args create mode 100644 tests/qemuxmlconfdata/iommufd-q35.x86_64-latest.xml create mode 100644 tests/qemuxmlconfdata/iommufd-q35.xml create mode 100644 tests/qemuxmlconfdata/iommufd-virt-pci-bus-single.aarch64-latest.args create mode 100644 tests/qemuxmlconfdata/iommufd-virt-pci-bus-single.aarch64-latest.xml create mode 100644 tests/qemuxmlconfdata/iommufd-virt-pci-bus-single.xml create mode 100644 tests/qemuxmlconfdata/iommufd-virt.aarch64-latest.args create mode 100644 tests/qemuxmlconfdata/iommufd-virt.aarch64-latest.xml create mode 100644 tests/qemuxmlconfdata/iommufd-virt.xml create mode 100644 tests/qemuxmlconfdata/iommufd.x86_64-latest.args create mode 100644 tests/qemuxmlconfdata/iommufd.x86_64-latest.xml create mode 100644 tests/qemuxmlconfdata/iommufd.xml -- 2.43.0

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[PATCH] qapi/net: deprecate TAP fd and vhostfd options
by Vladimir Sementsov-Ogievskiy 31 Jan '26

31 Jan '26

They are the same as fds and vhostfds, except they accept only one fd. Let's deprecate redundant options. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov(a)yandex-team.ru> --- Hi all! after "[PATCH v2 00/12] net: refactoring and fixes" options fd and vhostfd becomes redundant, fds and vhostfds may be used instead. this patch also based on "[PATCH v6] qapi: net: deprecate vhostforce option", that's why it's sent separately. Based-on: <20260129213215.1405459-1-vsementsov(a)yandex-team.ru> Based-on: <20251113071711.349651-1-vsementsov(a)yandex-team.ru> docs/about/deprecated.rst | 6 ++++++ qapi/net.json | 9 +++++---- 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index e8ff478583..9010f8ab07 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -451,6 +451,12 @@ TAP ``vhostforce`` (since 11.0) The ``vhostforce`` option is redundant with the ``vhost`` option. If they conflict, ``vhost`` takes precedence. Just use ``vhost``. +TAP ``fd`` and ``vhostfd`` (since 11.0) +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Use ``fds`` and ``vhostfds`` correspondingly, each set with one fd +instead of ``fd`` and ``vhsotfd``. + Vhost-user ``vhostforce`` (since 11.0) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/qapi/net.json b/qapi/net.json index 9a00d578e9..2d5aed3ef8 100644 --- a/qapi/net.json +++ b/qapi/net.json @@ -326,8 +326,7 @@ # # @fd: file descriptor of an already opened tap # -# @fds: multiple file descriptors of already opened multiqueue capable -# tap +# @fds: multiple file descriptors of already opened tap # # @script: script to initialize the interface # @@ -359,13 +358,15 @@ # Features: # # @deprecated: Member @vhostforce is deprecated. Use @vhost instead. +# Member @fd is deprecated. Use @fds instead. +# Member @vhostfd is deprecated. Use @vhostfds instead. # # Since: 1.2 ## { 'struct': 'NetdevTapOptions', 'data': { '*ifname': 'str', - '*fd': 'str', + '*fd': { 'type': 'str', 'features': [ 'deprecated' ] }, '*fds': 'str', '*script': 'str', '*downscript': 'str', @@ -374,7 +375,7 @@ '*sndbuf': 'size', '*vnet_hdr': 'bool', '*vhost': 'bool', - '*vhostfd': 'str', + '*vhostfd': { 'type': 'str', 'features': [ 'deprecated' ] }, '*vhostfds': 'str', '*vhostforce': { 'type': 'bool', 'features': [ 'deprecated' ] }, '*queues': 'uint32', -- 2.52.0

3 5

[PATCH] networkxmlconftest: Expect success for "hostdev" case only on Linux
by Michal Privoznik 31 Jan '26

31 Jan '26

From: Michal Privoznik <mprivozn(a)redhat.com> Our network has multiple means of forwarding the traffic and 'hostdev' is one of them. This mode means that the network is configured to use a set of PCI devices which are then assigned to individual domains to use (PCI device assignment). Now, as of v12.0.0-61-gecb2e06bdf our test runners (testCompareXMLToXMLFiles() and testCompareXMLToConfFiles()) call networkValidateTests(). For aforementioned type of network this means checking that the specified set of devices contains only VFs (see v3.2.0-rc1~24 for more info). It is true that our virpcimock is preloaded which mimics VFs, but our utils module (virpci.c specifically) talks to sysfs to check various PCI device attributes, including whether it's a VF. This obviously works on Linux and doesn't work anywhere else. Therefore, until our utils module is taught how to check PCI attribs on other systems, make the "hostdev" test case expect validation failure on non-Linux systems. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com> --- tests/networkxmlconftest.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/tests/networkxmlconftest.c b/tests/networkxmlconftest.c index b32a39c553..b74d5b14f5 100644 --- a/tests/networkxmlconftest.c +++ b/tests/networkxmlconftest.c @@ -313,7 +313,16 @@ mymain(void) DO_TEST("bandwidth-network"); DO_TEST("openvswitch-net"); DO_TEST_VALIDATE_ERROR("passthrough-pf"); +#ifdef __linux__ DO_TEST("hostdev"); +#else + /* Our test runners call networkValidateTests() which for + * <forward mode='hostdev'/> means validating that PCI + * devices are VFs. It's done so by querying sysfs which + * obviously works on Linux only. Thus, expect a validation + * error elsewhere. */ + DO_TEST_VALIDATE_ERROR("hostdev"); +#endif DO_TEST_FLAGS("hostdev-pf", VIR_NETWORK_XML_INACTIVE); DO_TEST_FLAGS("hostdev-pf-driver-model", VIR_NETWORK_XML_INACTIVE); DO_TEST("ptr-domains-auto"); -- 2.52.0

2 1

[PATCH v6] qapi: net: deprecate vhostforce option
by Vladimir Sementsov-Ogievskiy 30 Jan '26

30 Jan '26

This option for tap and vhost-user netdevs doesn't make sense since long ago (10 years!), starting from commits: 1e7398a140f7a6 ("vhost: enable vhost without without MSI-X") 24f938a682d934 ("vhost user:support vhost user nic for non msi guests") Prior these commits, to enable kernel vhost-net, or vhost-user-net for some specific kind of guests (that don't have MSI-X support), you should have set vhostforce=on. Now guest type doesn't matter, all guests are equal for these options logic. For tap the current logic is: vhost=on / vhost=off : vhostforce ignored, doesn't make sense vhost unset : vhostforce counts, enabling vhost So you may enable vhost for tap several ways: - vhost=on - vhostforce=on - vhost=on + vhostforce=on - and even vhost=on + vhostforce=off - they are all equal. For vhost-user we simply ignore the vhostforce option at all in the code. Let's finally deprecate the extra options. Also, fix @vhostforce documentation everywhere to show the real picture, and update vhost-user test to not use deprecated option. While updating command line options, drop "experimental" word from "experimental in kernel accelerator". vhost-net is in production for years. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov(a)yandex-team.ru> Reviewed-by: Markus Armbruster <armbru(a)redhat.com> --- v6: - update numbers 10.2 -> 11.0 - add r-b by Markus docs/about/deprecated.rst | 11 +++++++++++ qapi/net.json | 18 ++++++++++++++---- qemu-options.hx | 13 +++++-------- tests/qtest/vhost-user-test.c | 2 +- 4 files changed, 31 insertions(+), 13 deletions(-) diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 03e29915f0..3f97392a45 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -498,6 +498,17 @@ Backend ``memory`` (since 9.0) ``memory`` is a deprecated synonym for ``ringbuf``. +TAP ``vhostforce`` (since 11.0) +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The ``vhostforce`` option is redundant with the ``vhost`` option. +If they conflict, ``vhost`` takes precedence. Just use ``vhost``. + +Vhost-user ``vhostforce`` (since 11.0) +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The ``vhostforce`` option is a no-op. Do not use it. + CPU device properties ''''''''''''''''''''' diff --git a/qapi/net.json b/qapi/net.json index 118bd34965..9a00d578e9 100644 --- a/qapi/net.json +++ b/qapi/net.json @@ -348,13 +348,18 @@ # @vhostfds: file descriptors of multiple already opened vhost net # devices # -# @vhostforce: vhost on for non-MSIX virtio guests +# @vhostforce: enable vhost-net network accelerator. Ignored when +# @vhost is set. # # @queues: number of queues to be created for multiqueue capable tap # # @poll-us: maximum number of microseconds that could be spent on busy # polling for tap (since 2.7) # +# Features: +# +# @deprecated: Member @vhostforce is deprecated. Use @vhost instead. +# # Since: 1.2 ## { 'struct': 'NetdevTapOptions', @@ -371,7 +376,7 @@ '*vhost': 'bool', '*vhostfd': 'str', '*vhostfds': 'str', - '*vhostforce': 'bool', + '*vhostforce': { 'type': 'bool', 'features': [ 'deprecated' ] }, '*queues': 'uint32', '*poll-us': 'uint32'} } @@ -610,17 +615,22 @@ # # @chardev: name of a unix socket chardev # -# @vhostforce: vhost on for non-MSIX virtio guests (default: false). +# @vhostforce: silently ignored, exists just for backward +# compatibility. # # @queues: number of queues to be created for multiqueue vhost-user # (default: 1) (Since 2.5) # +# Features: +# +# @deprecated: Member @vhostforce is deprecated. +# # Since: 2.1 ## { 'struct': 'NetdevVhostUserOptions', 'data': { 'chardev': 'str', - '*vhostforce': 'bool', + '*vhostforce': { 'type': 'bool', 'features': [ 'deprecated' ] }, '*queues': 'int' } } ## diff --git a/qemu-options.hx b/qemu-options.hx index fca2b7bc74..414b762743 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -2882,7 +2882,7 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, #else "-netdev tap,id=str[,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile]\n" " [,br=bridge][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off]\n" - " [,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n" + " [,vhostfd=h][,vhostfds=x:y:...:z][,queues=n]\n" " [,poll-us=n]\n" " configure a host TAP network backend with ID 'str'\n" " connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE ")\n" @@ -2898,9 +2898,7 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, " default is disabled 'sndbuf=0' to enable flow control set 'sndbuf=1048576')\n" " use vnet_hdr=off to avoid enabling the IFF_VNET_HDR tap flag\n" " use vnet_hdr=on to make the lack of IFF_VNET_HDR support an error condition\n" - " use vhost=on to enable experimental in kernel accelerator\n" - " (only has effect for virtio guests which use MSIX)\n" - " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" + " use vhost=on to enable in kernel accelerator\n" " use 'vhostfd=h' to connect to an already opened vhost net device\n" " use 'vhostfds=x:y:...:z to connect to multiple already opened vhost net devices\n" " use 'queues=n' to specify the number of queues to be created for multiqueue TAP\n" @@ -2991,7 +2989,7 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev, " use 'start-queue=m' to specify the first queue that should be used\n" #endif #ifdef CONFIG_POSIX - "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n" + "-netdev vhost-user,id=str,chardev=dev\n" " configure a vhost-user network, backed by a chardev 'dev'\n" #endif #ifdef __linux__ @@ -3882,12 +3880,11 @@ SRST for insertion into the socket map. The combination of 'map-path' and 'sock-fds' together is not supported. -``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]`` +``-netdev vhost-user,chardev=id[,queues=n]`` Establish a vhost-user netdev, backed by a chardev id. The chardev should be a unix domain socket backed one. The vhost-user uses a specifically defined protocol to pass vhost ioctl replacement - messages to an application on the other end of the socket. On - non-MSIX guests, the feature can be forced with vhostforce. Use + messages to an application on the other end of the socket. Use 'queues=n' to specify the number of queues to be created for multiqueue vhost-user. diff --git a/tests/qtest/vhost-user-test.c b/tests/qtest/vhost-user-test.c index d2bb21d5b9..f977f50baf 100644 --- a/tests/qtest/vhost-user-test.c +++ b/tests/qtest/vhost-user-test.c @@ -46,7 +46,7 @@ #define QEMU_CMD_SHM " -m %d -object memory-backend-shm,id=mem,size=%dM," \ " -numa node,memdev=mem" #define QEMU_CMD_CHR " -chardev socket,id=%s,path=%s%s" -#define QEMU_CMD_NETDEV " -netdev vhost-user,id=hs0,chardev=%s,vhostforce=on" +#define QEMU_CMD_NETDEV " -netdev vhost-user,id=hs0,chardev=%s" #define HUGETLBFS_MAGIC 0x958458f6 -- 2.48.1

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