On 12/12/17 17:06, Alexey Kardashevskiy wrote:
> On 12/12/17 16:54, Alex Williamson wrote:
>> 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,
>
> This is the default setting, or you do not want it to be a property so the
> user cannot shoot himself in a foot?
>
>> (b) should never be enabled on ppc, regardless
>> of (a). Thanks,
>
>
> The intention is to have a property - msix_no_mmap=true, except a single
> case - ppc-pseries, I just do not know how to enforce it for a specific
> machine type.
I do know now. For example,
static void spapr_machine_2_11_instance_options(MachineState *machine)
{
register_compat_prop("vfio-pci", "msix-no-mmap", "off");
}
which is basically "-global vfio-pci.msix-no-mmap=off" but in the code.
> It could also be a machine property, like "kernel_irqchip".
>
>
>
>>
>> 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),
>>
>
>
--
Alexey
