[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v5 2/5] virtio-iommu: Implement RESV_MEM probe request
From: |
Markus Armbruster |
Subject: |
Re: [PATCH v5 2/5] virtio-iommu: Implement RESV_MEM probe request |
Date: |
Thu, 25 Jun 2020 09:05:56 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux) |
Eric Auger <eric.auger@redhat.com> writes:
> This patch implements the PROBE request. At the moment,
> only THE RESV_MEM property is handled. The first goal is
> to report iommu wide reserved regions such as the MSI regions
> set by the machine code. On x86 this will be the IOAPIC MSI
> region, [0xFEE00000 - 0xFEEFFFFF], on ARM this may be the ITS
> doorbell.
>
> In the future we may introduce per device reserved regions.
> This will be useful when protecting host assigned devices
> which may expose their own reserved regions
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
>
> ---
>
> v4 -> v5:
> - assert if reserved region type is different from RESERVED or
> MSI
>
> v3 -> v4:
> - removed any reference to the NONE property that does not
> exist anymore.
>
> v2 -> v3:
> - on probe, do not fill the reminder of the buffer with zeroes
> as the buffer was already zero initialized (Bharat)
>
> v1 -> v2:
> - move the unlock back to the same place
> - remove the push label and factorize the code after the out label
> - fix a bunch of cpu_to_leX according to the latest spec revision
> - do not remove sizeof(last) from free space
> - check the ep exists
> ---
> include/hw/virtio/virtio-iommu.h | 2 +
> hw/virtio/virtio-iommu.c | 92 ++++++++++++++++++++++++++++++--
> hw/virtio/trace-events | 1 +
> 3 files changed, 91 insertions(+), 4 deletions(-)
>
> diff --git a/include/hw/virtio/virtio-iommu.h
> b/include/hw/virtio/virtio-iommu.h
> index e653004d7c..49eb105cd8 100644
> --- a/include/hw/virtio/virtio-iommu.h
> +++ b/include/hw/virtio/virtio-iommu.h
> @@ -53,6 +53,8 @@ typedef struct VirtIOIOMMU {
> GHashTable *as_by_busptr;
> IOMMUPciBus *iommu_pcibus_by_bus_num[PCI_BUS_MAX];
> PCIBus *primary_bus;
> + ReservedRegion *reserved_regions;
> + uint32_t nb_reserved_regions;
> GTree *domains;
> QemuMutex mutex;
> GTree *endpoints;
> diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c
> index 483883ec1d..aabc3e36b1 100644
> --- a/hw/virtio/virtio-iommu.c
> +++ b/hw/virtio/virtio-iommu.c
> @@ -38,6 +38,7 @@
>
> /* Max size */
> #define VIOMMU_DEFAULT_QUEUE_SIZE 256
> +#define VIOMMU_PROBE_SIZE 512
>
> typedef struct VirtIOIOMMUDomain {
> uint32_t id;
> @@ -378,6 +379,63 @@ static int virtio_iommu_unmap(VirtIOIOMMU *s,
> return ret;
> }
>
> +static ssize_t virtio_iommu_fill_resv_mem_prop(VirtIOIOMMU *s, uint32_t ep,
> + uint8_t *buf, size_t free)
> +{
> + struct virtio_iommu_probe_resv_mem prop = {};
> + size_t size = sizeof(prop), length = size - sizeof(prop.head), total;
> + int i;
> +
> + total = size * s->nb_reserved_regions;
> +
> + if (total > free) {
> + return -ENOSPC;
> + }
> +
> + for (i = 0; i < s->nb_reserved_regions; i++) {
> + prop.head.type = cpu_to_le16(VIRTIO_IOMMU_PROBE_T_RESV_MEM);
> + prop.head.length = cpu_to_le16(length);
> + prop.subtype = s->reserved_regions[i].type;
> + assert(prop.subtype == VIRTIO_IOMMU_RESV_MEM_T_RESERVED ||
> + prop.subtype == VIRTIO_IOMMU_RESV_MEM_T_MSI);
The assertion makes sense here: we're mapping from the generic
ReservedRegion type (which is unsigned) to the specific
virtio_iommu_probe_resv_mem subtype (which is uint8_t, but only these
two values are valid).
Howver, the assertion should test s->reserved_regions[i].type and go
before the assignment, to ensure it doesn't truncate!
Can I trigger the assertion with -device? My try to find the answer
myself failed:
$ qemu-system-x86_64 -nodefaults -S -display none -device
virtio-iommu-pci,len-reserved-regions=1,reserved-regions[0]=0xfee00000:0xfeefffff:99
qemu-system-x86_64: -device
virtio-iommu-pci,len-reserved-regions=1,reserved-regions[0]=0xfee00000:0xfeefffff:99:
pc-i440fx-5.1 machine fails to create iommu-map device tree bindings
Check you machine implements a hotplug handler for the virtio-iommu-pci
device
Check the guest is booted without FW or with -no-acpi
By the way: s/Check you machine/Check your machine/.
[...]
[PATCH v5 3/5] virtio-iommu: Handle reserved regions in the translation process, Eric Auger, 2020/06/24
Re: [PATCH v5 0/5] VIRTIO-IOMMU probe request support and MSI bypass on ARM, Michael S. Tsirkin, 2020/06/24
Re: [PATCH v5 0/5] VIRTIO-IOMMU probe request support and MSI bypass on ARM, Michael S. Tsirkin, 2020/06/24