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Re: [Qemu-devel] [PATCH v12 2/9] hw/vfio/platform: vfio-platform skeleto
From: |
Alex Williamson |
Subject: |
Re: [Qemu-devel] [PATCH v12 2/9] hw/vfio/platform: vfio-platform skeleton |
Date: |
Thu, 16 Apr 2015 16:04:12 -0600 |
On Thu, 2015-03-19 at 17:16 +0000, Eric Auger wrote:
> Minimal VFIO platform implementation supporting register space
> user mapping but not IRQ assignment.
>
> Signed-off-by: Kim Phillips <address@hidden>
> Signed-off-by: Eric Auger <address@hidden>
>
> ---
> v11 -> v12:
> - add x-mmap property definition, without which the default value of
> vbasedev.allow_mmap is false, hence preventing the reg space from
> being mapped.
>
> v10 -> v11:
> x Take into account Alex Bennee's comments:
> - use g_malloc0_n instead of g_malloc0
> - use block declarations when possible
> - rework readlink returned value treatment
> - use g_strlcat in place of strncat
> x use g_snprintf in place of snprintf
> x correct error handling in vfio_populate_device,
> in case of flag not corresponding to platform device
> x various cosmetic changes
>
> v9 -> v10:
> - vfio_populate_device no more called in common vfio_get_device
> but in vfio_base_device_init
>
> v8 -> v9:
> - irq management is moved into a separate patch to ease the review
> - VFIO_DEVICE_FLAGS_PLATFORM is checked in vfio_populate_device
> - g_free of regions added in vfio_populate_device error label
> - virtualID becomes 32b
>
> v7 -> v8:
> - change proto of vfio_platform_compute_needs_reset and sets
> vbasedev->needs_reset to false there
> - vfio_[un]mask_irqindex renamed into vfio_[un]mask_single_irqindex
> - vfio_register_irq_starter renamed into vfio_kick_irqs
> we now use a reset notifier instead of a machine init done notifier.
> Enables to get rid of the VfioIrqStarterNotifierParams dangling
> pointer. Previously we use pbus first_irq. This is no more possible
> since the reset notifier takes a void * and first_irq is a field of
> a const struct. So now we pass the DeviceState handle of the
> interrupt controller. I tried to keep the code generic, reason why
> I did not rely on an architecture specific accessor to retrieve
> the gsi number (gic accessor as proposed by Alex). I would like to
> avoid creating an ARM VFIO device model. I hope this model
> model can work on other archs than arm (no multiple intc?);
> wouldn't it be simpler to keep the previous first_irq parameter and
> relax the const constraint.
>
> v6 -> v7:
> - compat is not exposed anymore as a user option. Rationale is
> the vfio device became abstract and a specialization is needed
> anyway. The derived device must set the compat string.
> - in v6 vfio_start_irq_injection was exposed in vfio-platform.h.
> A new function dubbed vfio_register_irq_starter replaces it. It
> registers a machine init done notifier that programs & starts
> all dynamic VFIO device IRQs. This function is supposed to be
> called by the machine file. A set of static helper routines are
> added too. It must be called before the creation of the platform
> bus device.
>
> v5 -> v6:
> - vfio_device property renamed into host property
> - correct error handling of VFIO_DEVICE_GET_IRQ_INFO ioctl
> and remove PCI related comment
> - remove declaration of vfio_setup_irqfd and irqfd_allowed
> property.Both belong to next patch (irqfd)
> - remove declaration of vfio_intp_interrupt in vfio-platform.h
> - functions that can be static get this characteristic
> - remove declarations of vfio_region_ops, vfio_memory_listener,
> group_list, vfio_address_spaces. All are moved to vfio-common.h
> - remove vfio_put_device declaration and definition
> - print_regions removed. code moved into vfio_populate_regions
> - replace DPRINTF by trace events
> - new helper routine to set the trigger eventfd
> - dissociate intp init from the injection enablement:
> vfio_enable_intp renamed into vfio_init_intp and new function
> named vfio_start_eventfd_injection
> - injection start moved to vfio_start_irq_injection (not anymore
> in vfio_populate_interrupt)
> - new start_irq_fn field in VFIOPlatformDevice corresponding to
> the function that will be used for starting injection
> - user handled eventfd:
> x add mutex to protect IRQ state & list manipulation,
> x correct misleading comment in vfio_intp_interrupt.
> x Fix bugs thanks to fake interrupt modality
> - VFIOPlatformDeviceClass becomes abstract
> - add error_setg in vfio_platform_realize
>
> v4 -> v5:
> - vfio-plaform.h included first
> - cleanup error handling in *populate*, vfio_get_device,
> vfio_enable_intp
> - vfio_put_device not called anymore
> - add some includes to follow vfio policy
>
> v3 -> v4:
> [Eric Auger]
> - merge of "vfio: Add initial IRQ support in platform device"
> to get a full functional patch although perfs are limited.
> - removal of unrealize function since I currently understand
> it is only used with device hot-plug feature.
>
> v2 -> v3:
> [Eric Auger]
> - further factorization between PCI and platform (VFIORegion,
> VFIODevice). same level of functionality.
>
> <= v2:
> [Kim Philipps]
> - Initial Creation of the device supporting register space mapping
> ---
> hw/vfio/Makefile.objs | 1 +
> hw/vfio/platform.c | 288
> ++++++++++++++++++++++++++++++++++++++++
> include/hw/vfio/vfio-common.h | 1 +
> include/hw/vfio/vfio-platform.h | 44 ++++++
> trace-events | 12 ++
> 5 files changed, 346 insertions(+)
> create mode 100644 hw/vfio/platform.c
> create mode 100644 include/hw/vfio/vfio-platform.h
>
> diff --git a/hw/vfio/Makefile.objs b/hw/vfio/Makefile.objs
> index e31f30e..c5c76fe 100644
> --- a/hw/vfio/Makefile.objs
> +++ b/hw/vfio/Makefile.objs
> @@ -1,4 +1,5 @@
> ifeq ($(CONFIG_LINUX), y)
> obj-$(CONFIG_SOFTMMU) += common.o
> obj-$(CONFIG_PCI) += pci.o
> +obj-$(CONFIG_SOFTMMU) += platform.o
> endif
> diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
> new file mode 100644
> index 0000000..5ec2a18
> --- /dev/null
> +++ b/hw/vfio/platform.c
> @@ -0,0 +1,288 @@
> +/*
> + * vfio based device assignment support - platform devices
> + *
> + * Copyright Linaro Limited, 2014
> + *
> + * Authors:
> + * Kim Phillips <address@hidden>
> + * Eric Auger <address@hidden>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2. See
> + * the COPYING file in the top-level directory.
> + *
> + * Based on vfio based PCI device assignment support:
> + * Copyright Red Hat, Inc. 2012
> + */
> +
> +#include <linux/vfio.h>
> +#include <sys/ioctl.h>
> +
> +#include "hw/vfio/vfio-platform.h"
> +#include "qemu/error-report.h"
> +#include "qemu/range.h"
> +#include "sysemu/sysemu.h"
> +#include "exec/memory.h"
> +#include "hw/sysbus.h"
> +#include "trace.h"
> +#include "hw/platform-bus.h"
> +
> +/* VFIO skeleton */
> +
> +/* not implemented yet */
> +static void vfio_platform_compute_needs_reset(VFIODevice *vbasedev)
> +{
> + vbasedev->needs_reset = false;
> +}
> +
> +/* not implemented yet */
> +static int vfio_platform_hot_reset_multi(VFIODevice *vbasedev)
> +{
> + return 0;
> +}
> +
> +/**
> + * vfio_populate_device - Allocate and populate MMIO region
> + * structs according to driver returned information
> + * @vbasedev: the VFIO device handle
> + *
> + */
> +static int vfio_populate_device(VFIODevice *vbasedev)
> +{
> + int i, ret = -1;
> + VFIOPlatformDevice *vdev =
> + container_of(vbasedev, VFIOPlatformDevice, vbasedev);
> +
> + if (!(vbasedev->flags & VFIO_DEVICE_FLAGS_PLATFORM)) {
> + error_report("vfio: Um, this isn't a platform device");
> + return ret;
> + }
> +
> + vdev->regions = g_malloc0_n(1,
> + sizeof(VFIORegion *) *
> vbasedev->num_regions);
> +
> + for (i = 0; i < vbasedev->num_regions; i++) {
> + struct vfio_region_info reg_info = { .argsz = sizeof(reg_info) };
> + VFIORegion *ptr;
> +
> + vdev->regions[i] = g_malloc0_n(1, sizeof(VFIORegion));
> + ptr = vdev->regions[i];
> + reg_info.index = i;
> + ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, ®_info);
> + if (ret) {
> + error_report("vfio: Error getting region %d info: %m", i);
> + goto reg_error;
> + }
> + ptr->flags = reg_info.flags;
> + ptr->size = reg_info.size;
> + ptr->fd_offset = reg_info.offset;
> + ptr->nr = i;
> + ptr->vbasedev = vbasedev;
> +
> + trace_vfio_platform_populate_regions(ptr->nr,
> + (unsigned long)ptr->flags,
> + (unsigned long)ptr->size,
> + ptr->vbasedev->fd,
> + (unsigned long)ptr->fd_offset);
> + }
> +
> + return 0;
> +reg_error:
> + for (i = 0; i < vbasedev->num_regions; i++) {
> + g_free(vdev->regions[i]);
> + }
> + g_free(vdev->regions);
> + return ret;
> +}
> +
> +/* specialized functions for VFIO Platform devices */
> +static VFIODeviceOps vfio_platform_ops = {
> + .vfio_compute_needs_reset = vfio_platform_compute_needs_reset,
> + .vfio_hot_reset_multi = vfio_platform_hot_reset_multi,
> +};
> +
> +/**
> + * vfio_base_device_init - perform preliminary VFIO setup
> + * @vbasedev: the VFIO device handle
> + *
> + * Implement the VFIO command sequence that allows to discover
> + * assigned device resources: group extraction, device
> + * fd retrieval, resource query.
> + * Precondition: the device name must be initialized
> + */
> +static int vfio_base_device_init(VFIODevice *vbasedev)
> +{
> + VFIOGroup *group;
> + VFIODevice *vbasedev_iter;
> + char path[PATH_MAX], iommu_group_path[PATH_MAX], *group_name;
> + ssize_t len;
> + struct stat st;
> + int groupid;
> + int ret;
> +
> + /* name must be set prior to the call */
> + if (!vbasedev->name) {
> + return -EINVAL;
> + }
> +
> + /* Check that the host device exists */
> + g_snprintf(path, sizeof(path), "/sys/bus/platform/devices/%s/",
> + vbasedev->name);
This seems exploitable. Maybe not for any real gain, but what happens
when name is "/" or "../something"?
> +
> + if (stat(path, &st) < 0) {
> + error_report("vfio: error: no such host device: %s", path);
> + return -errno;
> + }
> +
> + g_strlcat(path, "iommu_group", sizeof(path));
> + len = readlink(path, iommu_group_path, sizeof(iommu_group_path));
> + if (len < 0) {
> + error_report("vfio: error no iommu_group for device");
> + return -errno;
See 13665a2d2f67 ("vfio: Fix overrun after readlink() fills buffer
completely")
And the patch I just posted to make it -ENAMETOOLONG. It's impossible
to hit afaict, but coverity will complain.
> + }
> +
> + iommu_group_path[len] = 0;
> + group_name = basename(iommu_group_path);
> +
> + if (sscanf(group_name, "%d", &groupid) != 1) {
> + error_report("vfio: error reading %s: %m", path);
> + return -errno;
> + }
> +
> + trace_vfio_platform_base_device_init(vbasedev->name, groupid);
> +
> + group = vfio_get_group(groupid, &address_space_memory);
> + if (!group) {
> + error_report("vfio: failed to get group %d", groupid);
> + return -ENOENT;
> + }
> +
> + g_snprintf(path, sizeof(path), "%s", vbasedev->name);
> +
> + QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
> + if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
> + error_report("vfio: error: device %s is already attached", path);
> + vfio_put_group(group);
> + return -EBUSY;
> + }
> + }
> + ret = vfio_get_device(group, path, vbasedev);
> + if (ret) {
> + error_report("vfio: failed to get device %s", path);
> + vfio_put_group(group);
> + return ret;
> + }
> +
> + ret = vfio_populate_device(vbasedev);
> + if (ret) {
> + error_report("vfio: failed to populate device %s", path);
> + vfio_put_group(group);
> + }
> +
> + return ret;
> +}
> +
> +/**
> + * vfio_map_region - initialize the 2 memory regions for a given
> + * MMIO region index
> + * @vdev: the VFIO platform device handle
> + * @nr: the index of the region
> + *
> + * Init the top memory region and the mmapped memory region beneath
> + * VFIOPlatformDevice is used since VFIODevice is not a QOM Object
> + * and could not be passed to memory region functions
> +*/
> +static void vfio_map_region(VFIOPlatformDevice *vdev, int nr)
> +{
> + VFIORegion *region = vdev->regions[nr];
> + unsigned size = region->size;
Couldn't you have a 4G or greater region?
> + char name[64];
> +
> + if (!size) {
> + return;
> + }
> +
> + g_snprintf(name, sizeof(name), "VFIO %s region %d",
> + vdev->vbasedev.name, nr);
> +
> + /* A "slow" read/write mapping underlies all regions */
> + memory_region_init_io(®ion->mem, OBJECT(vdev), &vfio_region_ops,
> + region, name, size);
> +
> + g_strlcat(name, " mmap", sizeof(name));
> +
> + if (vfio_mmap_region(OBJECT(vdev), region, ®ion->mem,
> + ®ion->mmap_mem, ®ion->mmap, size, 0, name)) {
> + error_report("%s unsupported. Performance may be slow", name);
> + }
> +}
> +
> +/**
> + * vfio_platform_realize - the device realize function
> + * @dev: device state pointer
> + * @errp: error
> + *
> + * initialize the device, its memory regions and IRQ structures
> + * IRQ are started separately
> + */
> +static void vfio_platform_realize(DeviceState *dev, Error **errp)
> +{
> + VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(dev);
> + SysBusDevice *sbdev = SYS_BUS_DEVICE(dev);
> + VFIODevice *vbasedev = &vdev->vbasedev;
> + int i, ret;
> +
> + vbasedev->type = VFIO_DEVICE_TYPE_PLATFORM;
> + vbasedev->ops = &vfio_platform_ops;
> +
> + trace_vfio_platform_realize(vbasedev->name, vdev->compat);
> +
> + ret = vfio_base_device_init(vbasedev);
> + if (ret) {
> + error_setg(errp, "vfio: vfio_base_device_init failed for %s",
> + vbasedev->name);
> + return;
> + }
> +
> + for (i = 0; i < vbasedev->num_regions; i++) {
> + vfio_map_region(vdev, i);
> + sysbus_init_mmio(sbdev, &vdev->regions[i]->mem);
> + }
> +}
> +
> +static const VMStateDescription vfio_platform_vmstate = {
> + .name = TYPE_VFIO_PLATFORM,
> + .unmigratable = 1,
> +};
> +
> +static Property vfio_platform_dev_properties[] = {
> + DEFINE_PROP_STRING("host", VFIOPlatformDevice, vbasedev.name),
> + DEFINE_PROP_BOOL("x-mmap", VFIOPlatformDevice, vbasedev.allow_mmap,
> true),
> + DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void vfio_platform_class_init(ObjectClass *klass, void *data)
> +{
> + DeviceClass *dc = DEVICE_CLASS(klass);
> +
> + dc->realize = vfio_platform_realize;
> + dc->props = vfio_platform_dev_properties;
> + dc->vmsd = &vfio_platform_vmstate;
> + dc->desc = "VFIO-based platform device assignment";
> + set_bit(DEVICE_CATEGORY_MISC, dc->categories);
> +}
> +
> +static const TypeInfo vfio_platform_dev_info = {
> + .name = TYPE_VFIO_PLATFORM,
> + .parent = TYPE_SYS_BUS_DEVICE,
> + .instance_size = sizeof(VFIOPlatformDevice),
> + .class_init = vfio_platform_class_init,
> + .class_size = sizeof(VFIOPlatformDeviceClass),
> + .abstract = true,
> +};
> +
> +static void register_vfio_platform_dev_type(void)
> +{
> + type_register_static(&vfio_platform_dev_info);
> +}
> +
> +type_init(register_vfio_platform_dev_type)
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index 0d1fb80..59a321d 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -42,6 +42,7 @@
>
> enum {
> VFIO_DEVICE_TYPE_PCI = 0,
> + VFIO_DEVICE_TYPE_PLATFORM = 1,
> };
>
> typedef struct VFIORegion {
> diff --git a/include/hw/vfio/vfio-platform.h b/include/hw/vfio/vfio-platform.h
> new file mode 100644
> index 0000000..338f0c6
> --- /dev/null
> +++ b/include/hw/vfio/vfio-platform.h
> @@ -0,0 +1,44 @@
> +/*
> + * vfio based device assignment support - platform devices
> + *
> + * Copyright Linaro Limited, 2014
> + *
> + * Authors:
> + * Kim Phillips <address@hidden>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2. See
> + * the COPYING file in the top-level directory.
> + *
> + * Based on vfio based PCI device assignment support:
> + * Copyright Red Hat, Inc. 2012
> + */
> +
> +#ifndef HW_VFIO_VFIO_PLATFORM_H
> +#define HW_VFIO_VFIO_PLATFORM_H
> +
> +#include "hw/sysbus.h"
> +#include "hw/vfio/vfio-common.h"
> +
> +#define TYPE_VFIO_PLATFORM "vfio-platform"
> +
> +typedef struct VFIOPlatformDevice {
> + SysBusDevice sbdev;
> + VFIODevice vbasedev; /* not a QOM object */
> + VFIORegion **regions;
> + char *compat; /* compatibility string */
> +} VFIOPlatformDevice;
> +
> +typedef struct VFIOPlatformDeviceClass {
> + /*< private >*/
> + SysBusDeviceClass parent_class;
> + /*< public >*/
> +} VFIOPlatformDeviceClass;
> +
> +#define VFIO_PLATFORM_DEVICE(obj) \
> + OBJECT_CHECK(VFIOPlatformDevice, (obj), TYPE_VFIO_PLATFORM)
> +#define VFIO_PLATFORM_DEVICE_CLASS(klass) \
> + OBJECT_CLASS_CHECK(VFIOPlatformDeviceClass, (klass), TYPE_VFIO_PLATFORM)
> +#define VFIO_PLATFORM_DEVICE_GET_CLASS(obj) \
> + OBJECT_GET_CLASS(VFIOPlatformDeviceClass, (obj), TYPE_VFIO_PLATFORM)
> +
> +#endif /*HW_VFIO_VFIO_PLATFORM_H*/
> diff --git a/trace-events b/trace-events
> index 30eba92..17c7108 100644
> --- a/trace-events
> +++ b/trace-events
> @@ -1560,6 +1560,18 @@ vfio_put_group(int fd) "close group->fd=%d"
> vfio_get_device(const char * name, unsigned int flags, unsigned int
> num_regions, unsigned int num_irqs) "Device %s flags: %u, regions: %u, irqs:
> %u"
> vfio_put_base_device(int fd) "close vdev->fd=%d"
>
> +# hw/vfio/platform.c
> +vfio_platform_eoi(int pin, int fd) "EOI IRQ pin %d (fd=%d)"
> +vfio_platform_mmap_set_enabled(bool enabled) "fast path = %d"
> +vfio_platform_intp_mmap_enable(int pin) "IRQ #%d still active, stay in slow
> path"
> +vfio_platform_intp_interrupt(int pin, int fd) "Handle IRQ #%d (fd = %d)"
> +vfio_platform_populate_interrupts(int pin, int count, int flags) "- IRQ
> index %d: count %d, flags=0x%x"
> +vfio_platform_populate_regions(int region_index, unsigned long flag,
> unsigned long size, int fd, unsigned long offset) "- region %d flags = 0x%lx,
> size = 0x%lx, fd= %d, offset = 0x%lx"
> +vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group
> #%d"
> +vfio_platform_realize(char *name, char *compat) "vfio device %s, compat = %s"
> +vfio_intp_interrupt_set_pending(int index) "irq %d is set PENDING"
> +vfio_platform_eoi_handle_pending(int index) "handle PENDING IRQ %d"
> +
> #hw/acpi/memory_hotplug.c
> mhp_acpi_invalid_slot_selected(uint32_t slot) "0x%"PRIx32
> mhp_acpi_read_addr_lo(uint32_t slot, uint32_t addr) "slot[0x%"PRIx32"] addr
> lo: 0x%"PRIx32
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Alex Williamson <=