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Re: [RFC PATCH] vfio/common: Separate vfio-pci ranges
From: |
Joao Martins |
Subject: |
Re: [RFC PATCH] vfio/common: Separate vfio-pci ranges |
Date: |
Fri, 8 Sep 2023 09:35:29 +0100 |
On 08/09/2023 09:28, Cédric Le Goater wrote:
> On 9/8/23 10:16, Joao Martins wrote:
>> On 08/09/2023 08:14, Cédric Le Goater wrote:
>>> From: Joao Martins <joao.m.martins@oracle.com>
>>>
>>> QEMU computes the DMA logging ranges for two predefined ranges: 32-bit
>>> and 64-bit. In the OVMF case, when the dynamic MMIO window is enabled,
>>> QEMU includes in the 64-bit range the RAM regions at the lower part
>>> and vfio-pci device RAM regions which are at the top of the address
>>> space. This range contains a large gap and the size can be bigger than
>>> the dirty tracking HW limits of some devices (MLX5 has a 2^42 limit).
>>>
>>> To avoid such large ranges, introduce a new PCI range covering the
>>> vfio-pci device RAM regions, this only if the addresses are above 4GB
>>> to avoid breaking potential SeaBIOS guests.
>>>
>>> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
>>> [ clg: - wrote commit log
>>> - fixed overlapping 32-bit and PCI ranges when using SeaBIOS ]
>>> Signed-off-by: Cédric Le Goater <clg@redhat.com>
>>> ---
>>> hw/vfio/common.c | 51 +++++++++++++++++++++++++++++++++++++++-----
>>> hw/vfio/trace-events | 2 +-
>>> 2 files changed, 47 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
>>> index
>>> 237101d03844273f653d98b6d053a1ae9c05a247..a5548e3bebf999e6d9cef08bdaf1fbc3b437e5eb
>>> 100644
>>> --- a/hw/vfio/common.c
>>> +++ b/hw/vfio/common.c
>>> @@ -27,6 +27,7 @@
>>> #include "hw/vfio/vfio-common.h"
>>> #include "hw/vfio/vfio.h"
>>> +#include "hw/vfio/pci.h"
>>> #include "exec/address-spaces.h"
>>> #include "exec/memory.h"
>>> #include "exec/ram_addr.h"
>>> @@ -1400,6 +1401,8 @@ typedef struct VFIODirtyRanges {
>>> hwaddr max32;
>>> hwaddr min64;
>>> hwaddr max64;
>>> + hwaddr minpci;
>>> + hwaddr maxpci;
>>
>> Considering this is about pci64 hole relocation, I wondered post-reading your
>> feedback, that maybe we should rename {min,max}pci to {min,max}pci64 (...)
>
> yes.
>
>>
>>> } VFIODirtyRanges;
>>> typedef struct VFIODirtyRangesListener {
>>> @@ -1408,6 +1411,31 @@ typedef struct VFIODirtyRangesListener {
>>> MemoryListener listener;
>>> } VFIODirtyRangesListener;
>>> +static bool vfio_section_is_vfio_pci(MemoryRegionSection *section,
>>> + VFIOContainer *container)
>>> +{
>>> + VFIOPCIDevice *pcidev;
>>> + VFIODevice *vbasedev;
>>> + VFIOGroup *group;
>>> + Object *owner;
>>> +
>>> + owner = memory_region_owner(section->mr);
>>> +
>>> + QLIST_FOREACH(group, &container->group_list, container_next) {
>>> + QLIST_FOREACH(vbasedev, &group->device_list, next) {
>>> + if (vbasedev->type != VFIO_DEVICE_TYPE_PCI) {
>>> + continue;
>>> + }
>>> + pcidev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
>>> + if (OBJECT(pcidev) == owner) {
>>> + return true;
>>> + }
>>> + }
>>> + }
>>> +
>>> + return false;
>>> +}
>>> +
>>> static void vfio_dirty_tracking_update(MemoryListener *listener,
>>> MemoryRegionSection *section)
>>> {
>>> @@ -1434,9 +1462,14 @@ static void vfio_dirty_tracking_update(MemoryListener
>>> *listener,
>>> * would be an IOVATree but that has a much bigger runtime overhead
>>> and
>>> * unnecessary complexity.
>>> */
>>> - min = (end <= UINT32_MAX) ? &range->min32 : &range->min64;
>>> - max = (end <= UINT32_MAX) ? &range->max32 : &range->max64;
>>> -
>>> + if (vfio_section_is_vfio_pci(section, dirty->container) &&
>>> + iova >= UINT32_MAX) {
>>> + min = &range->minpci;
>>> + max = &range->maxpci;
>>
>> (...) specially considering this check of making sure we skip the pci-hole32
>> (as
>> that one is fixed)
>
> yep. That check above might deserve a comment also.
>
> Could you resend please ?
>
yes. This is on top of your vfio-8.2 branch right?
> Thanks,
>
> C.
>
>
>>
>>> + } else {
>>> + min = (end <= UINT32_MAX) ? &range->min32 : &range->min64;
>>> + max = (end <= UINT32_MAX) ? &range->max32 : &range->max64;
>>> + }
>>> if (*min > iova) {
>>> *min = iova;
>>> }
>>> @@ -1461,6 +1494,7 @@ static void vfio_dirty_tracking_init(VFIOContainer
>>> *container,
>>> memset(&dirty, 0, sizeof(dirty));
>>> dirty.ranges.min32 = UINT32_MAX;
>>> dirty.ranges.min64 = UINT64_MAX;
>>> + dirty.ranges.minpci = UINT64_MAX;
>>> dirty.listener = vfio_dirty_tracking_listener;
>>> dirty.container = container;
>>> @@ -1531,7 +1565,8 @@
>>> vfio_device_feature_dma_logging_start_create(VFIOContainer *container,
>>> * DMA logging uAPI guarantees to support at least a number of ranges
>>> that
>>> * fits into a single host kernel base page.
>>> */
>>> - control->num_ranges = !!tracking->max32 + !!tracking->max64;
>>> + control->num_ranges = !!tracking->max32 + !!tracking->max64 +
>>> + !!tracking->maxpci;
>>> ranges = g_try_new0(struct vfio_device_feature_dma_logging_range,
>>> control->num_ranges);
>>> if (!ranges) {
>>> @@ -1550,11 +1585,17 @@
>>> vfio_device_feature_dma_logging_start_create(VFIOContainer *container,
>>> if (tracking->max64) {
>>> ranges->iova = tracking->min64;
>>> ranges->length = (tracking->max64 - tracking->min64) + 1;
>>> + ranges++;
>>> + }
>>> + if (tracking->maxpci) {
>>> + ranges->iova = tracking->minpci;
>>> + ranges->length = (tracking->maxpci - tracking->minpci) + 1;
>>> }
>>> trace_vfio_device_dirty_tracking_start(control->num_ranges,
>>> tracking->min32,
>>> tracking->max32,
>>> - tracking->min64,
>>> tracking->max64);
>>> + tracking->min64,
>>> tracking->max64,
>>> + tracking->minpci,
>>> tracking->maxpci);
>>> return feature;
>>> }
>>> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
>>> index
>>> ce61b10827b6a1203a5fe1a87a76d96f25c11345..ab52c6bb7f0c11e51fefef231c108d0c9381547e
>>> 100644
>>> --- a/hw/vfio/trace-events
>>> +++ b/hw/vfio/trace-events
>>> @@ -104,7 +104,7 @@ vfio_known_safe_misalignment(const char *name, uint64_t
>>> iova, uint64_t offset_wi
>>> vfio_listener_region_add_no_dma_map(const char *name, uint64_t iova,
>>> uint64_t size, uint64_t page_size) "Region \"%s\" 0x%"PRIx64"
>>> size=0x%"PRIx64" is not aligned to 0x%"PRIx64" and cannot be mapped for DMA"
>>> vfio_listener_region_del(uint64_t start, uint64_t end) "region_del
>>> 0x%"PRIx64" - 0x%"PRIx64
>>> vfio_device_dirty_tracking_update(uint64_t start, uint64_t end, uint64_t
>>> min, uint64_t max) "section 0x%"PRIx64" - 0x%"PRIx64" -> update [0x%"PRIx64"
>>> - 0x%"PRIx64"]"
>>> -vfio_device_dirty_tracking_start(int nr_ranges, uint64_t min32, uint64_t
>>> max32, uint64_t min64, uint64_t max64) "nr_ranges %d 32:[0x%"PRIx64" -
>>> 0x%"PRIx64"], 64:[0x%"PRIx64" - 0x%"PRIx64"]"
>>> +vfio_device_dirty_tracking_start(int nr_ranges, uint64_t min32, uint64_t
>>> max32, uint64_t min64, uint64_t max64, uint64_t minpci, uint64_t maxpci)
>>> "nr_ranges %d 32:[0x%"PRIx64" - 0x%"PRIx64"], 64:[0x%"PRIx64" -
>>> 0x%"PRIx64"],
>>> pci:[0x%"PRIx64" - 0x%"PRIx64"]"
>>> vfio_disconnect_container(int fd) "close container->fd=%d"
>>> 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"
>>
>