| Message ID | 20220127142940.671333-3-jean-philippe@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | virtio-iommu: Support VIRTIO_IOMMU_F_BYPASS_CONFIG | expand |
On 1/27/22 3:29 PM, Jean-Philippe Brucker wrote: > Currently the virtio-iommu device must be programmed before it allows > DMA from any PCI device. This can make the VM entirely unusable when a > virtio-iommu driver isn't present, for example in a bootloader that > loads the OS from storage. > > Similarly to the other vIOMMU implementations, default to DMA bypassing > the IOMMU during boot. Add a "boot-bypass" property, defaulting to true, > that lets users change this behavior. > > Replace the VIRTIO_IOMMU_F_BYPASS feature, which didn't support bypass > before feature negotiation, with VIRTIO_IOMMU_F_BYPASS_CONFIG. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Eric > --- > include/hw/virtio/virtio-iommu.h | 1 + > hw/virtio/virtio-iommu.c | 51 +++++++++++++++++++++++++++++--- > hw/virtio/trace-events | 4 ++- > 3 files changed, 51 insertions(+), 5 deletions(-) > > diff --git a/include/hw/virtio/virtio-iommu.h b/include/hw/virtio/virtio-iommu.h > index e2339e5b72..84391f8448 100644 > --- a/include/hw/virtio/virtio-iommu.h > +++ b/include/hw/virtio/virtio-iommu.h > @@ -58,6 +58,7 @@ struct VirtIOIOMMU { > GTree *domains; > QemuMutex mutex; > GTree *endpoints; > + bool boot_bypass; > }; > > #endif > diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c > index aa9c16a17b..ec02029bb6 100644 > --- a/hw/virtio/virtio-iommu.c > +++ b/hw/virtio/virtio-iommu.c > @@ -24,6 +24,7 @@ > #include "hw/qdev-properties.h" > #include "hw/virtio/virtio.h" > #include "sysemu/kvm.h" > +#include "sysemu/reset.h" > #include "qapi/error.h" > #include "qemu/error-report.h" > #include "trace.h" > @@ -728,8 +729,7 @@ static IOMMUTLBEntry virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr, > .perm = IOMMU_NONE, > }; > > - bypass_allowed = virtio_vdev_has_feature(&s->parent_obj, > - VIRTIO_IOMMU_F_BYPASS); > + bypass_allowed = s->config.bypass; > > sid = virtio_iommu_get_bdf(sdev); > > @@ -831,13 +831,37 @@ static void virtio_iommu_get_config(VirtIODevice *vdev, uint8_t *config_data) > out_config->domain_range.start = cpu_to_le32(dev_config->domain_range.start); > out_config->domain_range.end = cpu_to_le32(dev_config->domain_range.end); > out_config->probe_size = cpu_to_le32(dev_config->probe_size); > + out_config->bypass = dev_config->bypass; > > trace_virtio_iommu_get_config(dev_config->page_size_mask, > dev_config->input_range.start, > dev_config->input_range.end, > dev_config->domain_range.start, > dev_config->domain_range.end, > - dev_config->probe_size); > + dev_config->probe_size, > + dev_config->bypass); > +} > + > +static void virtio_iommu_set_config(VirtIODevice *vdev, > + const uint8_t *config_data) > +{ > + VirtIOIOMMU *dev = VIRTIO_IOMMU(vdev); > + struct virtio_iommu_config *dev_config = &dev->config; > + const struct virtio_iommu_config *in_config = (void *)config_data; > + > + if (in_config->bypass != dev_config->bypass) { > + if (!virtio_vdev_has_feature(vdev, VIRTIO_IOMMU_F_BYPASS_CONFIG)) { > + virtio_error(vdev, "cannot set config.bypass"); > + return; > + } else if (in_config->bypass != 0 && in_config->bypass != 1) { > + virtio_error(vdev, "invalid config.bypass value '%u'", > + in_config->bypass); > + return; > + } > + dev_config->bypass = in_config->bypass; > + } > + > + trace_virtio_iommu_set_config(in_config->bypass); > } > > static uint64_t virtio_iommu_get_features(VirtIODevice *vdev, uint64_t f, > @@ -963,6 +987,19 @@ static int virtio_iommu_set_page_size_mask(IOMMUMemoryRegion *mr, > return 0; > } > > +static void virtio_iommu_system_reset(void *opaque) > +{ > + VirtIOIOMMU *s = opaque; > + > + trace_virtio_iommu_system_reset(); > + > + /* > + * config.bypass is sticky across device reset, but should be restored on > + * system reset > + */ > + s->config.bypass = s->boot_bypass; > +} > + > static void virtio_iommu_device_realize(DeviceState *dev, Error **errp) > { > VirtIODevice *vdev = VIRTIO_DEVICE(dev); > @@ -988,9 +1025,9 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp) > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_INPUT_RANGE); > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_DOMAIN_RANGE); > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MAP_UNMAP); > - virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS); > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MMIO); > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_PROBE); > + virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS_CONFIG); > > qemu_mutex_init(&s->mutex); > > @@ -1001,6 +1038,8 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp) > } else { > error_setg(errp, "VIRTIO-IOMMU is not attached to any PCI bus!"); > } > + > + qemu_register_reset(virtio_iommu_system_reset, s); > } > > static void virtio_iommu_device_unrealize(DeviceState *dev) > @@ -1008,6 +1047,8 @@ static void virtio_iommu_device_unrealize(DeviceState *dev) > VirtIODevice *vdev = VIRTIO_DEVICE(dev); > VirtIOIOMMU *s = VIRTIO_IOMMU(dev); > > + qemu_unregister_reset(virtio_iommu_system_reset, s); > + > g_hash_table_destroy(s->as_by_busptr); > if (s->domains) { > g_tree_destroy(s->domains); > @@ -1164,6 +1205,7 @@ static const VMStateDescription vmstate_virtio_iommu = { > > static Property virtio_iommu_properties[] = { > DEFINE_PROP_LINK("primary-bus", VirtIOIOMMU, primary_bus, "PCI", PCIBus *), > + DEFINE_PROP_BOOL("boot-bypass", VirtIOIOMMU, boot_bypass, true), > DEFINE_PROP_END_OF_LIST(), > }; > > @@ -1180,6 +1222,7 @@ static void virtio_iommu_class_init(ObjectClass *klass, void *data) > vdc->unrealize = virtio_iommu_device_unrealize; > vdc->reset = virtio_iommu_device_reset; > vdc->get_config = virtio_iommu_get_config; > + vdc->set_config = virtio_iommu_set_config; > vdc->get_features = virtio_iommu_get_features; > vdc->set_status = virtio_iommu_set_status; > vdc->vmsd = &vmstate_virtio_iommu_device; > diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events > index f7ad6be5fb..a5102eac9e 100644 > --- a/hw/virtio/trace-events > +++ b/hw/virtio/trace-events > @@ -89,9 +89,11 @@ virtio_mmio_setting_irq(int level) "virtio_mmio setting IRQ %d" > > # virtio-iommu.c > virtio_iommu_device_reset(void) "reset!" > +virtio_iommu_system_reset(void) "system reset!" > virtio_iommu_get_features(uint64_t features) "device supports features=0x%"PRIx64 > virtio_iommu_device_status(uint8_t status) "driver status = %d" > -virtio_iommu_get_config(uint64_t page_size_mask, uint64_t start, uint64_t end, uint32_t domain_start, uint32_t domain_end, uint32_t probe_size) "page_size_mask=0x%"PRIx64" input range start=0x%"PRIx64" input range end=0x%"PRIx64" domain range start=%d domain range end=%d probe_size=0x%x" > +virtio_iommu_get_config(uint64_t page_size_mask, uint64_t start, uint64_t end, uint32_t domain_start, uint32_t domain_end, uint32_t probe_size, uint8_t bypass) "page_size_mask=0x%"PRIx64" input range start=0x%"PRIx64" input range end=0x%"PRIx64" domain range start=%d domain range end=%d probe_size=0x%x bypass=0x%x" > +virtio_iommu_set_config(uint8_t bypass) "bypass=0x%x" > virtio_iommu_attach(uint32_t domain_id, uint32_t ep_id) "domain=%d endpoint=%d" > virtio_iommu_detach(uint32_t domain_id, uint32_t ep_id) "domain=%d endpoint=%d" > virtio_iommu_map(uint32_t domain_id, uint64_t virt_start, uint64_t virt_end, uint64_t phys_start, uint32_t flags) "domain=%d virt_start=0x%"PRIx64" virt_end=0x%"PRIx64 " phys_start=0x%"PRIx64" flags=%d"
On Thu, Jan 27 2022, Jean-Philippe Brucker <jean-philippe@linaro.org> wrote: > @@ -988,9 +1025,9 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp) > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_INPUT_RANGE); > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_DOMAIN_RANGE); > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MAP_UNMAP); > - virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS); > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MMIO); > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_PROBE); > + virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS_CONFIG); Hm. In the other patch, you say that you don't support cross-version migration (I assume across QEMU versions?) Because changing the feature set will be guest-visible, and would need some compat handling if you plan to support this.
On Tue, Feb 08, 2022 at 06:42:57PM +0100, Cornelia Huck wrote: > On Thu, Jan 27 2022, Jean-Philippe Brucker <jean-philippe@linaro.org> wrote: > > > @@ -988,9 +1025,9 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp) > > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_INPUT_RANGE); > > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_DOMAIN_RANGE); > > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MAP_UNMAP); > > - virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS); > > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MMIO); > > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_PROBE); > > + virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS_CONFIG); > > Hm. In the other patch, you say that you don't support cross-version > migration (I assume across QEMU versions?) I missed that ... where does it say this? > Because changing the feature > set will be guest-visible, and would need some compat handling if you > plan to support this.
On Tue, Feb 08 2022, "Michael S. Tsirkin" <mst@redhat.com> wrote: > On Tue, Feb 08, 2022 at 06:42:57PM +0100, Cornelia Huck wrote: >> On Thu, Jan 27 2022, Jean-Philippe Brucker <jean-philippe@linaro.org> wrote: >> >> > @@ -988,9 +1025,9 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp) >> > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_INPUT_RANGE); >> > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_DOMAIN_RANGE); >> > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MAP_UNMAP); >> > - virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS); >> > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MMIO); >> > virtio_add_feature(&s->features, VIRTIO_IOMMU_F_PROBE); >> > + virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS_CONFIG); >> >> Hm. In the other patch, you say that you don't support cross-version >> migration (I assume across QEMU versions?) > > I missed that ... where does it say this? In bf447d9b-c039-ccdc-f24f-ab8b56c1b196@redhat.com and follow-ups (unless I misread that; maybe it's more about this concrete boundary and not generally?) > >> Because changing the feature >> set will be guest-visible, and would need some compat handling if you >> plan to support this.
Hi, On 2/9/22 12:10 PM, Cornelia Huck wrote: > On Tue, Feb 08 2022, "Michael S. Tsirkin" <mst@redhat.com> wrote: > >> On Tue, Feb 08, 2022 at 06:42:57PM +0100, Cornelia Huck wrote: >>> On Thu, Jan 27 2022, Jean-Philippe Brucker <jean-philippe@linaro.org> wrote: >>> >>>> @@ -988,9 +1025,9 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp) >>>> virtio_add_feature(&s->features, VIRTIO_IOMMU_F_INPUT_RANGE); >>>> virtio_add_feature(&s->features, VIRTIO_IOMMU_F_DOMAIN_RANGE); >>>> virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MAP_UNMAP); >>>> - virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS); >>>> virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MMIO); >>>> virtio_add_feature(&s->features, VIRTIO_IOMMU_F_PROBE); >>>> + virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS_CONFIG); >>> Hm. In the other patch, you say that you don't support cross-version >>> migration (I assume across QEMU versions?) >> I missed that ... where does it say this? > In bf447d9b-c039-ccdc-f24f-ab8b56c1b196@redhat.com and follow-ups > (unless I misread that; maybe it's more about this concrete boundary and > not generally?) We were considering the virtio-iommu QEMU device currently isn't used for production yet, as far as we know, because we were missing the ACPI integration. So we envisionned to not care about mig subsections and just add the new field in the VMState. would that make sense? Thanks Eric > >>> Because changing the feature >>> set will be guest-visible, and would need some compat handling if you >>> plan to support this.
On Wed, Feb 09 2022, Eric Auger <eric.auger@redhat.com> wrote: > Hi, > > On 2/9/22 12:10 PM, Cornelia Huck wrote: >> On Tue, Feb 08 2022, "Michael S. Tsirkin" <mst@redhat.com> wrote: >> >>> On Tue, Feb 08, 2022 at 06:42:57PM +0100, Cornelia Huck wrote: >>>> On Thu, Jan 27 2022, Jean-Philippe Brucker <jean-philippe@linaro.org> wrote: >>>> >>>>> @@ -988,9 +1025,9 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp) >>>>> virtio_add_feature(&s->features, VIRTIO_IOMMU_F_INPUT_RANGE); >>>>> virtio_add_feature(&s->features, VIRTIO_IOMMU_F_DOMAIN_RANGE); >>>>> virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MAP_UNMAP); >>>>> - virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS); >>>>> virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MMIO); >>>>> virtio_add_feature(&s->features, VIRTIO_IOMMU_F_PROBE); >>>>> + virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS_CONFIG); >>>> Hm. In the other patch, you say that you don't support cross-version >>>> migration (I assume across QEMU versions?) >>> I missed that ... where does it say this? >> In bf447d9b-c039-ccdc-f24f-ab8b56c1b196@redhat.com and follow-ups >> (unless I misread that; maybe it's more about this concrete boundary and >> not generally?) > > We were considering the virtio-iommu QEMU device currently isn't used > for production yet, as far as we know, because we were missing the ACPI > integration. > So we envisionned to not care about mig subsections and just add the new > field in the VMState. > > would that make sense? If people are currently mostly playing with this device, it would not hurt too much, I guess. (Should we document expectations somewhere?) Adding a compat prop for this feature would be easy enough, but juggling subsections is a bit more involved, so I see the argument for not caring about them. > > Thanks > > Eric > >> >>>> Because changing the feature >>>> set will be guest-visible, and would need some compat handling if you >>>> plan to support this.
diff --git a/include/hw/virtio/virtio-iommu.h b/include/hw/virtio/virtio-iommu.h index e2339e5b72..84391f8448 100644 --- a/include/hw/virtio/virtio-iommu.h +++ b/include/hw/virtio/virtio-iommu.h @@ -58,6 +58,7 @@ struct VirtIOIOMMU { GTree *domains; QemuMutex mutex; GTree *endpoints; + bool boot_bypass; }; #endif diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c index aa9c16a17b..ec02029bb6 100644 --- a/hw/virtio/virtio-iommu.c +++ b/hw/virtio/virtio-iommu.c @@ -24,6 +24,7 @@ #include "hw/qdev-properties.h" #include "hw/virtio/virtio.h" #include "sysemu/kvm.h" +#include "sysemu/reset.h" #include "qapi/error.h" #include "qemu/error-report.h" #include "trace.h" @@ -728,8 +729,7 @@ static IOMMUTLBEntry virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr, .perm = IOMMU_NONE, }; - bypass_allowed = virtio_vdev_has_feature(&s->parent_obj, - VIRTIO_IOMMU_F_BYPASS); + bypass_allowed = s->config.bypass; sid = virtio_iommu_get_bdf(sdev); @@ -831,13 +831,37 @@ static void virtio_iommu_get_config(VirtIODevice *vdev, uint8_t *config_data) out_config->domain_range.start = cpu_to_le32(dev_config->domain_range.start); out_config->domain_range.end = cpu_to_le32(dev_config->domain_range.end); out_config->probe_size = cpu_to_le32(dev_config->probe_size); + out_config->bypass = dev_config->bypass; trace_virtio_iommu_get_config(dev_config->page_size_mask, dev_config->input_range.start, dev_config->input_range.end, dev_config->domain_range.start, dev_config->domain_range.end, - dev_config->probe_size); + dev_config->probe_size, + dev_config->bypass); +} + +static void virtio_iommu_set_config(VirtIODevice *vdev, + const uint8_t *config_data) +{ + VirtIOIOMMU *dev = VIRTIO_IOMMU(vdev); + struct virtio_iommu_config *dev_config = &dev->config; + const struct virtio_iommu_config *in_config = (void *)config_data; + + if (in_config->bypass != dev_config->bypass) { + if (!virtio_vdev_has_feature(vdev, VIRTIO_IOMMU_F_BYPASS_CONFIG)) { + virtio_error(vdev, "cannot set config.bypass"); + return; + } else if (in_config->bypass != 0 && in_config->bypass != 1) { + virtio_error(vdev, "invalid config.bypass value '%u'", + in_config->bypass); + return; + } + dev_config->bypass = in_config->bypass; + } + + trace_virtio_iommu_set_config(in_config->bypass); } static uint64_t virtio_iommu_get_features(VirtIODevice *vdev, uint64_t f, @@ -963,6 +987,19 @@ static int virtio_iommu_set_page_size_mask(IOMMUMemoryRegion *mr, return 0; } +static void virtio_iommu_system_reset(void *opaque) +{ + VirtIOIOMMU *s = opaque; + + trace_virtio_iommu_system_reset(); + + /* + * config.bypass is sticky across device reset, but should be restored on + * system reset + */ + s->config.bypass = s->boot_bypass; +} + static void virtio_iommu_device_realize(DeviceState *dev, Error **errp) { VirtIODevice *vdev = VIRTIO_DEVICE(dev); @@ -988,9 +1025,9 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp) virtio_add_feature(&s->features, VIRTIO_IOMMU_F_INPUT_RANGE); virtio_add_feature(&s->features, VIRTIO_IOMMU_F_DOMAIN_RANGE); virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MAP_UNMAP); - virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS); virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MMIO); virtio_add_feature(&s->features, VIRTIO_IOMMU_F_PROBE); + virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS_CONFIG); qemu_mutex_init(&s->mutex); @@ -1001,6 +1038,8 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp) } else { error_setg(errp, "VIRTIO-IOMMU is not attached to any PCI bus!"); } + + qemu_register_reset(virtio_iommu_system_reset, s); } static void virtio_iommu_device_unrealize(DeviceState *dev) @@ -1008,6 +1047,8 @@ static void virtio_iommu_device_unrealize(DeviceState *dev) VirtIODevice *vdev = VIRTIO_DEVICE(dev); VirtIOIOMMU *s = VIRTIO_IOMMU(dev); + qemu_unregister_reset(virtio_iommu_system_reset, s); + g_hash_table_destroy(s->as_by_busptr); if (s->domains) { g_tree_destroy(s->domains); @@ -1164,6 +1205,7 @@ static const VMStateDescription vmstate_virtio_iommu = { static Property virtio_iommu_properties[] = { DEFINE_PROP_LINK("primary-bus", VirtIOIOMMU, primary_bus, "PCI", PCIBus *), + DEFINE_PROP_BOOL("boot-bypass", VirtIOIOMMU, boot_bypass, true), DEFINE_PROP_END_OF_LIST(), }; @@ -1180,6 +1222,7 @@ static void virtio_iommu_class_init(ObjectClass *klass, void *data) vdc->unrealize = virtio_iommu_device_unrealize; vdc->reset = virtio_iommu_device_reset; vdc->get_config = virtio_iommu_get_config; + vdc->set_config = virtio_iommu_set_config; vdc->get_features = virtio_iommu_get_features; vdc->set_status = virtio_iommu_set_status; vdc->vmsd = &vmstate_virtio_iommu_device; diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events index f7ad6be5fb..a5102eac9e 100644 --- a/hw/virtio/trace-events +++ b/hw/virtio/trace-events @@ -89,9 +89,11 @@ virtio_mmio_setting_irq(int level) "virtio_mmio setting IRQ %d" # virtio-iommu.c virtio_iommu_device_reset(void) "reset!" +virtio_iommu_system_reset(void) "system reset!" virtio_iommu_get_features(uint64_t features) "device supports features=0x%"PRIx64 virtio_iommu_device_status(uint8_t status) "driver status = %d" -virtio_iommu_get_config(uint64_t page_size_mask, uint64_t start, uint64_t end, uint32_t domain_start, uint32_t domain_end, uint32_t probe_size) "page_size_mask=0x%"PRIx64" input range start=0x%"PRIx64" input range end=0x%"PRIx64" domain range start=%d domain range end=%d probe_size=0x%x" +virtio_iommu_get_config(uint64_t page_size_mask, uint64_t start, uint64_t end, uint32_t domain_start, uint32_t domain_end, uint32_t probe_size, uint8_t bypass) "page_size_mask=0x%"PRIx64" input range start=0x%"PRIx64" input range end=0x%"PRIx64" domain range start=%d domain range end=%d probe_size=0x%x bypass=0x%x" +virtio_iommu_set_config(uint8_t bypass) "bypass=0x%x" virtio_iommu_attach(uint32_t domain_id, uint32_t ep_id) "domain=%d endpoint=%d" virtio_iommu_detach(uint32_t domain_id, uint32_t ep_id) "domain=%d endpoint=%d" virtio_iommu_map(uint32_t domain_id, uint64_t virt_start, uint64_t virt_end, uint64_t phys_start, uint32_t flags) "domain=%d virt_start=0x%"PRIx64" virt_end=0x%"PRIx64 " phys_start=0x%"PRIx64" flags=%d"
Currently the virtio-iommu device must be programmed before it allows DMA from any PCI device. This can make the VM entirely unusable when a virtio-iommu driver isn't present, for example in a bootloader that loads the OS from storage. Similarly to the other vIOMMU implementations, default to DMA bypassing the IOMMU during boot. Add a "boot-bypass" property, defaulting to true, that lets users change this behavior. Replace the VIRTIO_IOMMU_F_BYPASS feature, which didn't support bypass before feature negotiation, with VIRTIO_IOMMU_F_BYPASS_CONFIG. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> --- include/hw/virtio/virtio-iommu.h | 1 + hw/virtio/virtio-iommu.c | 51 +++++++++++++++++++++++++++++--- hw/virtio/trace-events | 4 ++- 3 files changed, 51 insertions(+), 5 deletions(-)