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Thu, 22 Aug 2019 19:13:12 +0000 (UTC) Received: from work-vm (ovpn-117-231.ams2.redhat.com [10.36.117.231]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E6D7319C5B; Thu, 22 Aug 2019 19:13:05 +0000 (UTC) Date: Thu, 22 Aug 2019 20:13:03 +0100 From: "Dr. David Alan Gilbert" To: Kirti Wankhede Message-ID: <20190822191303.GO3277@work-vm> References: <1562665760-26158-1-git-send-email-kwankhede@nvidia.com> <1562665760-26158-5-git-send-email-kwankhede@nvidia.com> <20190711120713.GM3971@work-vm> <20190822093235.GC3277@work-vm> <092a9a37-d018-1d6e-7c61-7f8ada8819a7@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <092a9a37-d018-1d6e-7c61-7f8ada8819a7@nvidia.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Thu, 22 Aug 2019 19:13:13 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH v7 04/13] vfio: Add save and load functions for VFIO PCI devices X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Zhengxiao.zx@alibaba-inc.com, kevin.tian@intel.com, yi.l.liu@intel.com, cjia@nvidia.com, eskultet@redhat.com, ziye.yang@intel.com, cohuck@redhat.com, shuangtai.tst@alibaba-inc.com, qemu-devel@nongnu.org, zhi.a.wang@intel.com, mlevitsk@redhat.com, pasic@linux.ibm.com, aik@ozlabs.ru, alex.williamson@redhat.com, eauger@redhat.com, felipe@nutanix.com, jonathan.davies@nutanix.com, yan.y.zhao@intel.com, changpeng.liu@intel.com, Ken.Xue@amd.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Kirti Wankhede (kwankhede@nvidia.com) wrote: > > > On 8/22/2019 3:02 PM, Dr. David Alan Gilbert wrote: > > * Kirti Wankhede (kwankhede@nvidia.com) wrote: > >> Sorry for delay to respond. > >> > >> On 7/11/2019 5:37 PM, Dr. David Alan Gilbert wrote: > >>> * Kirti Wankhede (kwankhede@nvidia.com) wrote: > >>>> These functions save and restore PCI device specific data - config > >>>> space of PCI device. > >>>> Tested save and restore with MSI and MSIX type. > >>>> > >>>> Signed-off-by: Kirti Wankhede > >>>> Reviewed-by: Neo Jia > >>>> --- > >>>> hw/vfio/pci.c | 114 ++++++++++++++++++++++++++++++++++++++++++ > >>>> include/hw/vfio/vfio-common.h | 2 + > >>>> 2 files changed, 116 insertions(+) > >>>> > >>>> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c > >>>> index de0d286fc9dd..5fe4f8076cac 100644 > >>>> --- a/hw/vfio/pci.c > >>>> +++ b/hw/vfio/pci.c > >>>> @@ -2395,11 +2395,125 @@ static Object *vfio_pci_get_object(VFIODevice *vbasedev) > >>>> return OBJECT(vdev); > >>>> } > >>>> > >>>> +static void vfio_pci_save_config(VFIODevice *vbasedev, QEMUFile *f) > >>>> +{ > >>>> + VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev); > >>>> + PCIDevice *pdev = &vdev->pdev; > >>>> + uint16_t pci_cmd; > >>>> + int i; > >>>> + > >>>> + for (i = 0; i < PCI_ROM_SLOT; i++) { > >>>> + uint32_t bar; > >>>> + > >>>> + bar = pci_default_read_config(pdev, PCI_BASE_ADDRESS_0 + i * 4, 4); > >>>> + qemu_put_be32(f, bar); > >>>> + } > >>>> + > >>>> + qemu_put_be32(f, vdev->interrupt); > >>>> + if (vdev->interrupt == VFIO_INT_MSI) { > >>>> + uint32_t msi_flags, msi_addr_lo, msi_addr_hi = 0, msi_data; > >>>> + bool msi_64bit; > >>>> + > >>>> + msi_flags = pci_default_read_config(pdev, pdev->msi_cap + PCI_MSI_FLAGS, > >>>> + 2); > >>>> + msi_64bit = (msi_flags & PCI_MSI_FLAGS_64BIT); > >>>> + > >>>> + msi_addr_lo = pci_default_read_config(pdev, > >>>> + pdev->msi_cap + PCI_MSI_ADDRESS_LO, 4); > >>>> + qemu_put_be32(f, msi_addr_lo); > >>>> + > >>>> + if (msi_64bit) { > >>>> + msi_addr_hi = pci_default_read_config(pdev, > >>>> + pdev->msi_cap + PCI_MSI_ADDRESS_HI, > >>>> + 4); > >>>> + } > >>>> + qemu_put_be32(f, msi_addr_hi); > >>>> + > >>>> + msi_data = pci_default_read_config(pdev, > >>>> + pdev->msi_cap + (msi_64bit ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32), > >>>> + 2); > >>>> + qemu_put_be32(f, msi_data); > >>>> + } else if (vdev->interrupt == VFIO_INT_MSIX) { > >>>> + uint16_t offset; > >>>> + > >>>> + /* save enable bit and maskall bit */ > >>>> + offset = pci_default_read_config(pdev, > >>>> + pdev->msix_cap + PCI_MSIX_FLAGS + 1, 2); > >>>> + qemu_put_be16(f, offset); > >>>> + msix_save(pdev, f); > >>>> + } > >>>> + pci_cmd = pci_default_read_config(pdev, PCI_COMMAND, 2); > >>>> + qemu_put_be16(f, pci_cmd); > >>>> +} > >>>> + > >>>> +static void vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f) > >>>> +{ > >>>> + VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev); > >>>> + PCIDevice *pdev = &vdev->pdev; > >>>> + uint32_t interrupt_type; > >>>> + uint32_t msi_flags, msi_addr_lo, msi_addr_hi = 0, msi_data; > >>>> + uint16_t pci_cmd; > >>>> + bool msi_64bit; > >>>> + int i; > >>>> + > >>>> + /* retore pci bar configuration */ > >>>> + pci_cmd = pci_default_read_config(pdev, PCI_COMMAND, 2); > >>>> + vfio_pci_write_config(pdev, PCI_COMMAND, > >>>> + pci_cmd & (!(PCI_COMMAND_IO | PCI_COMMAND_MEMORY)), 2); > >>>> + for (i = 0; i < PCI_ROM_SLOT; i++) { > >>>> + uint32_t bar = qemu_get_be32(f); > >>>> + > >>>> + vfio_pci_write_config(pdev, PCI_BASE_ADDRESS_0 + i * 4, bar, 4); > >>>> + } > >>> > >>> Is it possible to validate the bar's at all? We just had a bug on a > >>> virtual device where one version was asking for a larger bar than the > >>> other; our validation caught this in some cases so we could tell that > >>> the guest had a BAR that was aligned at the wrong alignment. > >>> > >> > >> "Validate the bars" does that means validate size of bars? > > > > I meant validate the address programmed into the BAR against the size, > > assuming you know the size; e.g. if it's a 128MB BAR, then make sure the > > address programmed in is 128MB aligned. > > > > If this validation fails, migration resume should fail, right? Yes I think so; if you've got a device that wants 128MB alignment and someone gives you a non-aligned address, who knows what will happen. > > >>>> + vfio_pci_write_config(pdev, PCI_COMMAND, > >>>> + pci_cmd | PCI_COMMAND_IO | PCI_COMMAND_MEMORY, 2); > >>> > >>> Can you explain what this is for? You write the command register at the > >>> end of the function with the original value; there's no guarantee that > >>> the device is using IO for example, so ORing it seems odd. > >>> > >> > >> IO space and memory space accesses are disabled before writing BAR > >> addresses, only those are enabled here. > > > > But do you need to enable them here, or can it wait until the pci_cmd > > write at the end of the function? > > > > Ok, it can wait. Great. Dave > Thanks, > Kirti > > > >>> Also, are the other flags in COMMAND safe at this point - e.g. what > >>> about interrupts and stuff? > >>> > >> > >> COMMAND registers is saved from stop-and-copy phase, interrupt should be > >> disabled, then restoring here when vCPU are not yet running. > > > > Dave > > > >>>> + interrupt_type = qemu_get_be32(f); > >>>> + > >>>> + if (interrupt_type == VFIO_INT_MSI) { > >>>> + /* restore msi configuration */ > >>>> + msi_flags = pci_default_read_config(pdev, > >>>> + pdev->msi_cap + PCI_MSI_FLAGS, 2); > >>>> + msi_64bit = (msi_flags & PCI_MSI_FLAGS_64BIT); > >>>> + > >>>> + vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_FLAGS, > >>>> + msi_flags & (!PCI_MSI_FLAGS_ENABLE), 2); > >>>> + > >>>> + msi_addr_lo = qemu_get_be32(f); > >>>> + vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, > >>>> + msi_addr_lo, 4); > >>>> + > >>>> + msi_addr_hi = qemu_get_be32(f); > >>>> + if (msi_64bit) { > >>>> + vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, > >>>> + msi_addr_hi, 4); > >>>> + } > >>>> + msi_data = qemu_get_be32(f); > >>>> + vfio_pci_write_config(pdev, > >>>> + pdev->msi_cap + (msi_64bit ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32), > >>>> + msi_data, 2); > >>>> + > >>>> + vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_FLAGS, > >>>> + msi_flags | PCI_MSI_FLAGS_ENABLE, 2); > >>>> + } else if (interrupt_type == VFIO_INT_MSIX) { > >>>> + uint16_t offset = qemu_get_be16(f); > >>>> + > >>>> + /* load enable bit and maskall bit */ > >>>> + vfio_pci_write_config(pdev, pdev->msix_cap + PCI_MSIX_FLAGS + 1, > >>>> + offset, 2); > >>>> + msix_load(pdev, f); > >>>> + } > >>>> + pci_cmd = qemu_get_be16(f); > >>>> + vfio_pci_write_config(pdev, PCI_COMMAND, pci_cmd, 2); > >>>> +} > >>>> + > >>>> static VFIODeviceOps vfio_pci_ops = { > >>>> .vfio_compute_needs_reset = vfio_pci_compute_needs_reset, > >>>> .vfio_hot_reset_multi = vfio_pci_hot_reset_multi, > >>>> .vfio_eoi = vfio_intx_eoi, > >>>> .vfio_get_object = vfio_pci_get_object, > >>>> + .vfio_save_config = vfio_pci_save_config, > >>>> + .vfio_load_config = vfio_pci_load_config, > >>>> }; > >>>> > >>>> int vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp) > >>>> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h > >>>> index 771b6d59a3db..ee72bd984a36 100644 > >>>> --- a/include/hw/vfio/vfio-common.h > >>>> +++ b/include/hw/vfio/vfio-common.h > >>>> @@ -120,6 +120,8 @@ struct VFIODeviceOps { > >>>> int (*vfio_hot_reset_multi)(VFIODevice *vdev); > >>>> void (*vfio_eoi)(VFIODevice *vdev); > >>>> Object *(*vfio_get_object)(VFIODevice *vdev); > >>>> + void (*vfio_save_config)(VFIODevice *vdev, QEMUFile *f); > >>>> + void (*vfio_load_config)(VFIODevice *vdev, QEMUFile *f); > >>>> }; > >>>> > >>>> typedef struct VFIOGroup { > >>>> -- > >>>> 2.7.0 > >>>> > >>> -- > >>> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK > >>> > > -- > > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK