On Tue, 12 Dec 2017 16:21:31 +1100 Alexey Kardashevskiy <a...@ozlabs.ru> wrote:
> This makes use of a new VFIO_REGION_INFO_CAP_MSIX_MAPPABLE capability > which tells that a region with MSIX data can be mapped entirely, i.e. > the VFIO PCI driver won't prevent MSIX vectors area from being mapped. > > This adds a "msix-no-mmap" property to the vfio-pci device, it is "true" > by default and "false" for pseries-2.12+ machines. > > This requites kernel's "vfio-pci: Allow mapping MSIX BAR" > https://www.spinics.net/lists/kvm/msg160282.html > > Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> > --- > > This is an RFC as it requires kernel headers update which is not there yet. > > I'd like to make it "msix-mmap" (without "no") but could not find a way > of enabling a device property for machine versions newer than some value. > > I changed 2.11 machine just for the demonstration purpose. > > > --- > hw/vfio/pci.h | 1 + > include/hw/vfio/vfio-common.h | 1 + > linux-headers/linux/vfio.h | 5 +++++ > hw/ppc/spapr.c | 10 +++++++++- > hw/vfio/common.c | 15 +++++++++++++++ > hw/vfio/pci.c | 11 +++++++++++ > 6 files changed, 42 insertions(+), 1 deletion(-) > > diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h > index a8fb3b3..53912ef 100644 > --- a/hw/vfio/pci.h > +++ b/hw/vfio/pci.h > @@ -142,6 +142,7 @@ typedef struct VFIOPCIDevice { > bool no_kvm_intx; > bool no_kvm_msi; > bool no_kvm_msix; > + bool msix_no_mmap; > } VFIOPCIDevice; > > uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len); > diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h > index f3a2ac9..927d600 100644 > --- a/include/hw/vfio/vfio-common.h > +++ b/include/hw/vfio/vfio-common.h > @@ -171,6 +171,7 @@ int vfio_get_region_info(VFIODevice *vbasedev, int index, > struct vfio_region_info **info); > int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type, > uint32_t subtype, struct vfio_region_info > **info); > +bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int > region); > #endif > extern const MemoryListener vfio_prereg_listener; > > diff --git a/linux-headers/linux/vfio.h b/linux-headers/linux/vfio.h > index 4e7ab4c..bce9baf 100644 > --- a/linux-headers/linux/vfio.h > +++ b/linux-headers/linux/vfio.h > @@ -300,6 +300,11 @@ struct vfio_region_info_cap_type { > #define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG (2) > #define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG (3) > > +/* > + * The MSIX mappable capability informs that MSIX data of a BAR can be > mmapped. > + */ > +#define VFIO_REGION_INFO_CAP_MSIX_MAPPABLE 3 > + > /** > * VFIO_DEVICE_GET_IRQ_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 9, > * struct vfio_irq_info) > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 9de63f0..1dfc386 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -3742,13 +3742,21 @@ static const TypeInfo spapr_machine_info = { > /* > * pseries-2.11 > */ > +#define SPAPR_COMPAT_2_11 \ > + HW_COMPAT_2_10 \ > + { \ > + .driver = "vfio-pci", \ > + .property = "msix-no-mmap", \ > + .value = "on", \ > + }, \ > + > static void spapr_machine_2_11_instance_options(MachineState *machine) > { > } > > static void spapr_machine_2_11_class_options(MachineClass *mc) > { > - /* Defaults for the latest behaviour inherited from the base class */ > + SET_MACHINE_COMPAT(mc, SPAPR_COMPAT_2_11); > } > > DEFINE_SPAPR_MACHINE(2_11, "2.11", true); > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index ed7717d..593514c 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -1408,6 +1408,21 @@ int vfio_get_dev_region_info(VFIODevice *vbasedev, > uint32_t type, > return -ENODEV; > } > > +bool vfio_is_cap_present(VFIODevice *vbasedev, uint16_t cap_type, int region) > +{ > + struct vfio_region_info *info = NULL; > + bool ret = false; > + > + if (!vfio_get_region_info(vbasedev, region, &info)) { > + if (vfio_get_region_info_cap(info, cap_type)) { > + ret = true; > + } > + g_free(info); > + } > + > + return ret; > +} > + > /* > * Interfaces for IBM EEH (Enhanced Error Handling) > */ > diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c > index c977ee3..d9aeae8 100644 > --- a/hw/vfio/pci.c > +++ b/hw/vfio/pci.c > @@ -1289,6 +1289,12 @@ static void vfio_pci_fixup_msix_region(VFIOPCIDevice > *vdev) > off_t start, end; > VFIORegion *region = &vdev->bars[vdev->msix->table_bar].region; > > + if (!vdev->msix_no_mmap && > + vfio_is_cap_present(&vdev->vbasedev, > VFIO_REGION_INFO_CAP_MSIX_MAPPABLE, > + vdev->msix->table_bar)) { > + return; > + } > + > /* > * We expect to find a single mmap covering the whole BAR, anything else > * means it's either unsupported or already setup. > @@ -1473,6 +1479,10 @@ static int vfio_msix_setup(VFIOPCIDevice *vdev, int > pos, Error **errp) > */ > memory_region_set_enabled(&vdev->pdev.msix_pba_mmio, false); > > + if (!vdev->msix_no_mmap) { > + memory_region_set_enabled(&vdev->pdev.msix_table_mmio, false); > + } No, you're conflating issues. There's (a) can we mmap over the MSI-X vector table and (b) do we require QEMU emulation of the MSI-X vector table. (a) does NOT imply (b). AFAICT, (a) should be enabled any time the kernel supports it, (b) should never be enabled on ppc, regardless of (a). Thanks, Alex > + > return 0; > } > > @@ -2986,6 +2996,7 @@ static Property vfio_pci_dev_properties[] = { > DEFINE_PROP_BIT("x-igd-opregion", VFIOPCIDevice, features, > VFIO_FEATURE_ENABLE_IGD_OPREGION_BIT, false), > DEFINE_PROP_BOOL("x-no-mmap", VFIOPCIDevice, vbasedev.no_mmap, false), > + DEFINE_PROP_BOOL("msix-no-mmap", VFIOPCIDevice, msix_no_mmap, true), > DEFINE_PROP_BOOL("x-no-kvm-intx", VFIOPCIDevice, no_kvm_intx, false), > DEFINE_PROP_BOOL("x-no-kvm-msi", VFIOPCIDevice, no_kvm_msi, false), > DEFINE_PROP_BOOL("x-no-kvm-msix", VFIOPCIDevice, no_kvm_msix, false),
