Hi,
On 2/6/20 6:21 PM, Andre Przywara wrote:
> On Thu, 23 Jan 2020 13:48:00 +0000
> Alexandru Elisei <alexandru.elisei@xxxxxxx> wrote:
>
> Hi,
>
>> Implement callbacks for activating and deactivating emulation for a BAR
>> region. This is in preparation for allowing a guest operating system to
>> enable and disable access to I/O or memory space, or to reassign the
>> BARs.
>>
>> The emulated vesa device has been refactored in the process and the static
>> variables were removed in order to make using the callbacks less painful.
>> The framebuffer isn't designed to allow stopping and restarting at
>> arbitrary points in the guest execution. Furthermore, on x86, the kernel
>> will not change the BAR addresses, which on bare metal are programmed by
>> the firmware, so take the easy way out and refuse to deactivate emulation
>> for the BAR regions.
>>
>> Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
>> ---
>> hw/vesa.c | 120 ++++++++++++++++++++++++++++++++--------------
>> include/kvm/pci.h | 19 +++++++-
>> pci.c | 44 +++++++++++++++++
>> vfio/pci.c | 100 +++++++++++++++++++++++++++++++-------
>> virtio/pci.c | 90 ++++++++++++++++++++++++----------
>> 5 files changed, 294 insertions(+), 79 deletions(-)
>>
>> diff --git a/hw/vesa.c b/hw/vesa.c
>> index e988c0425946..74ebebbefa6b 100644
>> --- a/hw/vesa.c
>> +++ b/hw/vesa.c
>> @@ -18,6 +18,12 @@
>> #include <inttypes.h>
>> #include <unistd.h>
>>
>> +struct vesa_dev {
>> + struct pci_device_header pci_hdr;
>> + struct device_header dev_hdr;
>> + struct framebuffer fb;
>> +};
>> +
>> static bool vesa_pci_io_in(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
>> {
>> return true;
>> @@ -33,29 +39,52 @@ static struct ioport_operations vesa_io_ops = {
>> .io_out = vesa_pci_io_out,
>> };
>>
>> -static struct pci_device_header vesa_pci_device = {
>> - .vendor_id = cpu_to_le16(PCI_VENDOR_ID_REDHAT_QUMRANET),
>> - .device_id = cpu_to_le16(PCI_DEVICE_ID_VESA),
>> - .header_type = PCI_HEADER_TYPE_NORMAL,
>> - .revision_id = 0,
>> - .class[2] = 0x03,
>> - .subsys_vendor_id = cpu_to_le16(PCI_SUBSYSTEM_VENDOR_ID_REDHAT_QUMRANET),
>> - .subsys_id = cpu_to_le16(PCI_SUBSYSTEM_ID_VESA),
>> - .bar[1] = cpu_to_le32(VESA_MEM_ADDR | PCI_BASE_ADDRESS_SPACE_MEMORY),
>> - .bar_size[1] = VESA_MEM_SIZE,
>> -};
>> +static int vesa__bar_activate(struct kvm *kvm,
>> + struct pci_device_header *pci_hdr,
>> + int bar_num, void *data)
>> +{
>> + struct vesa_dev *vdev = data;
>> + u32 bar_addr, bar_size;
>> + char *mem;
>> + int r;
>>
>> -static struct device_header vesa_device = {
>> - .bus_type = DEVICE_BUS_PCI,
>> - .data = &vesa_pci_device,
>> -};
>> + bar_addr = pci__bar_address(pci_hdr, bar_num);
>> + bar_size = pci_hdr->bar_size[bar_num];
>>
>> -static struct framebuffer vesafb;
>> + switch (bar_num) {
>> + case 0:
>> + r = ioport__register(kvm, bar_addr, &vesa_io_ops, bar_size,
>> + NULL);
>> + break;
>> + case 1:
>> + mem = mmap(NULL, bar_size, PROT_RW, MAP_ANON_NORESERVE, -1, 0);
>> + if (mem == MAP_FAILED) {
>> + r = -errno;
>> + break;
>> + }
>> + r = kvm__register_dev_mem(kvm, bar_addr, bar_size, mem);
>> + if (r < 0)
>> + break;
>> + vdev->fb.mem = mem;
>> + break;
>> + default:
>> + r = -EINVAL;
>> + }
>> +
>> + return r;
>> +}
>> +
>> +static int vesa__bar_deactivate(struct kvm *kvm,
>> + struct pci_device_header *pci_hdr,
>> + int bar_num, void *data)
>> +{
>> + return -EINVAL;
>> +}
>>
>> struct framebuffer *vesa__init(struct kvm *kvm)
>> {
>> - u16 vesa_base_addr;
>> - char *mem;
>> + struct vesa_dev *vdev;
>> + u16 port_addr;
>> int r;
>>
>> BUILD_BUG_ON(!is_power_of_two(VESA_MEM_SIZE));
>> @@ -63,34 +92,51 @@ struct framebuffer *vesa__init(struct kvm *kvm)
>>
>> if (!kvm->cfg.vnc && !kvm->cfg.sdl && !kvm->cfg.gtk)
>> return NULL;
>> - r = pci_get_io_port_block(PCI_IO_SIZE);
>> - r = ioport__register(kvm, r, &vesa_io_ops, PCI_IO_SIZE, NULL);
>> - if (r < 0)
>> - return ERR_PTR(r);
>>
>> - vesa_base_addr = (u16)r;
>> - vesa_pci_device.bar[0] = cpu_to_le32(vesa_base_addr | PCI_BASE_ADDRESS_SPACE_IO);
>> - vesa_pci_device.bar_size[0] = PCI_IO_SIZE;
>> - r = device__register(&vesa_device);
>> - if (r < 0)
>> - return ERR_PTR(r);
>> + vdev = calloc(1, sizeof(*vdev));
>> + if (vdev == NULL)
>> + return ERR_PTR(-ENOMEM);
> Is it really necessary to allocate this here? You never free this, and I don't see how you could actually do this. AFAICS conceptually there can be only one VESA device? So maybe have a static variable above and use that instead of passing the pointer around? Or use &vdev if you need a pointer argument for the callbacks.
As far as I can tell, there can be only one VESA device, yes. I was following the
same pattern from virtio/{net,blk,rng,scsi,9p}.c, which I prefer because it's
explicit what function can access the device. What's wrong with passing the
pointer around? The entire PCI emulation code works like that.
>
>>
>> - mem = mmap(NULL, VESA_MEM_SIZE, PROT_RW, MAP_ANON_NORESERVE, -1, 0);
>> - if (mem == MAP_FAILED)
>> - return ERR_PTR(-errno);
>> + port_addr = pci_get_io_port_block(PCI_IO_SIZE);
>>
>> - r = kvm__register_dev_mem(kvm, VESA_MEM_ADDR, VESA_MEM_SIZE, mem);
>> - if (r < 0)
>> - return ERR_PTR(r);
>> + vdev->pci_hdr = (struct pci_device_header) {
>> + .vendor_id = cpu_to_le16(PCI_VENDOR_ID_REDHAT_QUMRANET),
>> + .device_id = cpu_to_le16(PCI_DEVICE_ID_VESA),
>> + .command = PCI_COMMAND_IO | PCI_COMMAND_MEMORY,
>> + .header_type = PCI_HEADER_TYPE_NORMAL,
>> + .revision_id = 0,
>> + .class[2] = 0x03,
>> + .subsys_vendor_id = cpu_to_le16(PCI_SUBSYSTEM_VENDOR_ID_REDHAT_QUMRANET),
>> + .subsys_id = cpu_to_le16(PCI_SUBSYSTEM_ID_VESA),
>> + .bar[0] = cpu_to_le32(port_addr | PCI_BASE_ADDRESS_SPACE_IO),
>> + .bar_size[0] = PCI_IO_SIZE,
>> + .bar[1] = cpu_to_le32(VESA_MEM_ADDR | PCI_BASE_ADDRESS_SPACE_MEMORY),
>> + .bar_size[1] = VESA_MEM_SIZE,
>> + };
>>
>> - vesafb = (struct framebuffer) {
>> + vdev->fb = (struct framebuffer) {
>> .width = VESA_WIDTH,
>> .height = VESA_HEIGHT,
>> .depth = VESA_BPP,
>> - .mem = mem,
>> + .mem = NULL,
>> .mem_addr = VESA_MEM_ADDR,
>> .mem_size = VESA_MEM_SIZE,
>> .kvm = kvm,
>> };
>> - return fb__register(&vesafb);
>> +
>> + r = pci__register_bar_regions(kvm, &vdev->pci_hdr, vesa__bar_activate,
>> + vesa__bar_deactivate, vdev);
>> + if (r < 0)
>> + return ERR_PTR(r);
>> +
>> + vdev->dev_hdr = (struct device_header) {
>> + .bus_type = DEVICE_BUS_PCI,
>> + .data = &vdev->pci_hdr,
>> + };
>> +
>> + r = device__register(&vdev->dev_hdr);
>> + if (r < 0)
>> + return ERR_PTR(r);
>> +
>> + return fb__register(&vdev->fb);
>> }
>> diff --git a/include/kvm/pci.h b/include/kvm/pci.h
>> index 235cd82fff3c..bf42f497168f 100644
>> --- a/include/kvm/pci.h
>> +++ b/include/kvm/pci.h
>> @@ -89,12 +89,19 @@ struct pci_cap_hdr {
>> u8 next;
>> };
>>
>> +struct pci_device_header;
>> +
>> +typedef int (*bar_activate_fn_t)(struct kvm *kvm,
>> + struct pci_device_header *pci_hdr,
>> + int bar_num, void *data);
>> +typedef int (*bar_deactivate_fn_t)(struct kvm *kvm,
>> + struct pci_device_header *pci_hdr,
>> + int bar_num, void *data);
>> +
>> #define PCI_BAR_OFFSET(b) (offsetof(struct pci_device_header, bar[b]))
>> #define PCI_DEV_CFG_SIZE 256
>> #define PCI_DEV_CFG_MASK (PCI_DEV_CFG_SIZE - 1)
>>
>> -struct pci_device_header;
>> -
>> struct pci_config_operations {
>> void (*write)(struct kvm *kvm, struct pci_device_header *pci_hdr,
>> u8 offset, void *data, int sz);
>> @@ -136,6 +143,9 @@ struct pci_device_header {
>>
>> /* Private to lkvm */
>> u32 bar_size[6];
>> + bar_activate_fn_t bar_activate_fn;
>> + bar_deactivate_fn_t bar_deactivate_fn;
>> + void *data;
>> struct pci_config_operations cfg_ops;
>> /*
>> * PCI INTx# are level-triggered, but virtual device often feature
>> @@ -160,8 +170,13 @@ void pci__assign_irq(struct device_header *dev_hdr);
>> void pci__config_wr(struct kvm *kvm, union pci_config_address addr, void *data, int size);
>> void pci__config_rd(struct kvm *kvm, union pci_config_address addr, void *data, int size);
>>
>> +
> Stray empty line?
Indeed, will get rid of it.
Thanks,
Alex
>
> Cheers,
> Andre
>
>> void *pci_find_cap(struct pci_device_header *hdr, u8 cap_type);
>>
>> +int pci__register_bar_regions(struct kvm *kvm, struct pci_device_header *pci_hdr,
>> + bar_activate_fn_t bar_activate_fn,
>> + bar_deactivate_fn_t bar_deactivate_fn, void *data);
>> +
>> static inline bool __pci__memory_space_enabled(u16 command)
>> {
>> return command & PCI_COMMAND_MEMORY;
>> diff --git a/pci.c b/pci.c
>> index 4f7b863298f6..5412f2defa2e 100644
>> --- a/pci.c
>> +++ b/pci.c
>> @@ -66,6 +66,11 @@ void pci__assign_irq(struct device_header *dev_hdr)
>> pci_hdr->irq_type = IRQ_TYPE_EDGE_RISING;
>> }
>>
>> +static bool pci_bar_is_implemented(struct pci_device_header *pci_hdr, int bar_num)
>> +{
>> + return bar_num < 6 && pci_hdr->bar_size[bar_num];
>> +}
>> +
>> static void *pci_config_address_ptr(u16 port)
>> {
>> unsigned long offset;
>> @@ -264,6 +269,45 @@ struct pci_device_header *pci__find_dev(u8 dev_num)
>> return hdr->data;
>> }
>>
>> +int pci__register_bar_regions(struct kvm *kvm, struct pci_device_header *pci_hdr,
>> + bar_activate_fn_t bar_activate_fn,
>> + bar_deactivate_fn_t bar_deactivate_fn, void *data)
>> +{
>> + int i, r;
>> + bool has_bar_regions = false;
>> +
>> + assert(bar_activate_fn && bar_deactivate_fn);
>> +
>> + pci_hdr->bar_activate_fn = bar_activate_fn;
>> + pci_hdr->bar_deactivate_fn = bar_deactivate_fn;
>> + pci_hdr->data = data;
>> +
>> + for (i = 0; i < 6; i++) {
>> + if (!pci_bar_is_implemented(pci_hdr, i))
>> + continue;
>> +
>> + has_bar_regions = true;
>> +
>> + if (pci__bar_is_io(pci_hdr, i) &&
>> + pci__io_space_enabled(pci_hdr)) {
>> + r = bar_activate_fn(kvm, pci_hdr, i, data);
>> + if (r < 0)
>> + return r;
>> + }
>> +
>> + if (pci__bar_is_memory(pci_hdr, i) &&
>> + pci__memory_space_enabled(pci_hdr)) {
>> + r = bar_activate_fn(kvm, pci_hdr, i, data);
>> + if (r < 0)
>> + return r;
>> + }
>> + }
>> +
>> + assert(has_bar_regions);
>> +
>> + return 0;
>> +}
>> +
>> int pci__init(struct kvm *kvm)
>> {
>> int r;
>> diff --git a/vfio/pci.c b/vfio/pci.c
>> index 8a775a4a4a54..9e595562180b 100644
>> --- a/vfio/pci.c
>> +++ b/vfio/pci.c
>> @@ -446,6 +446,83 @@ out_unlock:
>> mutex_unlock(&pdev->msi.mutex);
>> }
>>
>> +static int vfio_pci_bar_activate(struct kvm *kvm,
>> + struct pci_device_header *pci_hdr,
>> + int bar_num, void *data)
>> +{
>> + struct vfio_device *vdev = data;
>> + struct vfio_pci_device *pdev = &vdev->pci;
>> + struct vfio_pci_msix_pba *pba = &pdev->msix_pba;
>> + struct vfio_pci_msix_table *table = &pdev->msix_table;
>> + struct vfio_region *region = &vdev->regions[bar_num];
>> + int ret;
>> +
>> + if (!region->info.size) {
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> +
>> + if ((pdev->irq_modes & VFIO_PCI_IRQ_MODE_MSIX) &&
>> + (u32)bar_num == table->bar) {
>> + ret = kvm__register_mmio(kvm, table->guest_phys_addr,
>> + table->size, false,
>> + vfio_pci_msix_table_access, pdev);
>> + if (ret < 0 || table->bar!= pba->bar)
>> + goto out;
>> + }
>> +
>> + if ((pdev->irq_modes & VFIO_PCI_IRQ_MODE_MSIX) &&
>> + (u32)bar_num == pba->bar) {
>> + ret = kvm__register_mmio(kvm, pba->guest_phys_addr,
>> + pba->size, false,
>> + vfio_pci_msix_pba_access, pdev);
>> + goto out;
>> + }
>> +
>> + ret = vfio_map_region(kvm, vdev, region);
>> +out:
>> + return ret;
>> +}
>> +
>> +static int vfio_pci_bar_deactivate(struct kvm *kvm,
>> + struct pci_device_header *pci_hdr,
>> + int bar_num, void *data)
>> +{
>> + struct vfio_device *vdev = data;
>> + struct vfio_pci_device *pdev = &vdev->pci;
>> + struct vfio_pci_msix_pba *pba = &pdev->msix_pba;
>> + struct vfio_pci_msix_table *table = &pdev->msix_table;
>> + struct vfio_region *region = &vdev->regions[bar_num];
>> + int ret;
>> + bool success;
>> +
>> + if (!region->info.size) {
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> +
>> + if ((pdev->irq_modes & VFIO_PCI_IRQ_MODE_MSIX) &&
>> + (u32)bar_num == table->bar) {
>> + success = kvm__deregister_mmio(kvm, table->guest_phys_addr);
>> + ret = (success ? 0 : -EINVAL);
>> + if (ret < 0 || table->bar!= pba->bar)
>> + goto out;
>> + }
>> +
>> + if ((pdev->irq_modes & VFIO_PCI_IRQ_MODE_MSIX) &&
>> + (u32)bar_num == pba->bar) {
>> + success = kvm__deregister_mmio(kvm, pba->guest_phys_addr);
>> + ret = (success ? 0 : -EINVAL);
>> + goto out;
>> + }
>> +
>> + vfio_unmap_region(kvm, region);
>> + ret = 0;
>> +
>> +out:
>> + return ret;
>> +}
>> +
>> static void vfio_pci_cfg_read(struct kvm *kvm, struct pci_device_header *pci_hdr,
>> u8 offset, void *data, int sz)
>> {
>> @@ -804,12 +881,6 @@ static int vfio_pci_create_msix_table(struct kvm *kvm, struct vfio_device *vdev)
>> ret = -ENOMEM;
>> goto out_free;
>> }
>> - pba->guest_phys_addr = table->guest_phys_addr + table->size;
>> -
>> - ret = kvm__register_mmio(kvm, table->guest_phys_addr, table->size,
>> - false, vfio_pci_msix_table_access, pdev);
>> - if (ret < 0)
>> - goto out_free;
>>
>> /*
>> * We could map the physical PBA directly into the guest, but it's
>> @@ -819,10 +890,7 @@ static int vfio_pci_create_msix_table(struct kvm *kvm, struct vfio_device *vdev)
>> * between MSI-X table and PBA. For the sake of isolation, create a
>> * virtual PBA.
>> */
>> - ret = kvm__register_mmio(kvm, pba->guest_phys_addr, pba->size, false,
>> - vfio_pci_msix_pba_access, pdev);
>> - if (ret < 0)
>> - goto out_free;
>> + pba->guest_phys_addr = table->guest_phys_addr + table->size;
>>
>> pdev->msix.entries = entries;
>> pdev->msix.nr_entries = nr_entries;
>> @@ -893,11 +961,6 @@ static int vfio_pci_configure_bar(struct kvm *kvm, struct vfio_device *vdev,
>> region->guest_phys_addr = pci_get_mmio_block(map_size);
>> }
>>
>> - /* Map the BARs into the guest or setup a trap region. */
>> - ret = vfio_map_region(kvm, vdev, region);
>> - if (ret)
>> - return ret;
>> -
>> return 0;
>> }
>>
>> @@ -944,7 +1007,12 @@ static int vfio_pci_configure_dev_regions(struct kvm *kvm,
>> }
>>
>> /* We've configured the BARs, fake up a Configuration Space */
>> - return vfio_pci_fixup_cfg_space(vdev);
>> + ret = vfio_pci_fixup_cfg_space(vdev);
>> + if (ret)
>> + return ret;
>> +
>> + return pci__register_bar_regions(kvm, &pdev->hdr, vfio_pci_bar_activate,
>> + vfio_pci_bar_deactivate, vdev);
>> }
>>
>> /*
>> diff --git a/virtio/pci.c b/virtio/pci.c
>> index c4822514856c..5a3cc6f1e943 100644
>> --- a/virtio/pci.c
>> +++ b/virtio/pci.c
>> @@ -474,6 +474,65 @@ static void virtio_pci__io_mmio_callback(struct kvm_cpu *vcpu,
>> virtio_pci__data_out(vcpu, vdev, addr - mmio_addr, data, len);
>> }
>>
>> +static int virtio_pci__bar_activate(struct kvm *kvm,
>> + struct pci_device_header *pci_hdr,
>> + int bar_num, void *data)
>> +{
>> + struct virtio_device *vdev = data;
>> + u32 bar_addr, bar_size;
>> + int r;
>> +
>> + bar_addr = pci__bar_address(pci_hdr, bar_num);
>> + bar_size = pci_hdr->bar_size[bar_num];
>> +
>> + switch (bar_num) {
>> + case 0:
>> + r = ioport__register(kvm, bar_addr, &virtio_pci__io_ops,
>> + bar_size, vdev);
>> + if (r > 0)
>> + r = 0;
>> + break;
>> + case 1:
>> + r = kvm__register_mmio(kvm, bar_addr, bar_size, false,
>> + virtio_pci__io_mmio_callback, vdev);
>> + break;
>> + case 2:
>> + r = kvm__register_mmio(kvm, bar_addr, bar_size, false,
>> + virtio_pci__msix_mmio_callback, vdev);
>> + break;
>> + default:
>> + r = -EINVAL;
>> + }
>> +
>> + return r;
>> +}
>> +
>> +static int virtio_pci__bar_deactivate(struct kvm *kvm,
>> + struct pci_device_header *pci_hdr,
>> + int bar_num, void *data)
>> +{
>> + u32 bar_addr;
>> + bool success;
>> + int r;
>> +
>> + bar_addr = pci__bar_address(pci_hdr, bar_num);
>> +
>> + switch (bar_num) {
>> + case 0:
>> + r = ioport__unregister(kvm, bar_addr);
>> + break;
>> + case 1:
>> + case 2:
>> + success = kvm__deregister_mmio(kvm, bar_addr);
>> + r = (success ? 0 : -EINVAL);
>> + break;
>> + default:
>> + r = -EINVAL;
>> + }
>> +
>> + return r;
>> +}
>> +
>> int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
>> int device_id, int subsys_id, int class)
>> {
>> @@ -488,23 +547,8 @@ int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
>> BUILD_BUG_ON(!is_power_of_two(PCI_IO_SIZE));
>>
>> port_addr = pci_get_io_port_block(PCI_IO_SIZE);
>> - r = ioport__register(kvm, port_addr, &virtio_pci__io_ops, PCI_IO_SIZE,
>> - vdev);
>> - if (r < 0)
>> - return r;
>> - port_addr = (u16)r;
>> -
>> mmio_addr = pci_get_mmio_block(PCI_IO_SIZE);
>> - r = kvm__register_mmio(kvm, mmio_addr, PCI_IO_SIZE, false,
>> - virtio_pci__io_mmio_callback, vdev);
>> - if (r < 0)
>> - goto free_ioport;
>> -
>> msix_io_block = pci_get_mmio_block(PCI_IO_SIZE * 2);
>> - r = kvm__register_mmio(kvm, msix_io_block, PCI_IO_SIZE * 2, false,
>> - virtio_pci__msix_mmio_callback, vdev);
>> - if (r < 0)
>> - goto free_mmio;
>>
>> vpci->pci_hdr = (struct pci_device_header) {
>> .vendor_id = cpu_to_le16(PCI_VENDOR_ID_REDHAT_QUMRANET),
>> @@ -530,6 +574,12 @@ int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
>> .bar_size[2] = cpu_to_le32(PCI_IO_SIZE*2),
>> };
>>
>> + r = pci__register_bar_regions(kvm, &vpci->pci_hdr,
>> + virtio_pci__bar_activate,
>> + virtio_pci__bar_deactivate, vdev);
>> + if (r < 0)
>> + return r;
>> +
>> vpci->dev_hdr = (struct device_header) {
>> .bus_type = DEVICE_BUS_PCI,
>> .data = &vpci->pci_hdr,
>> @@ -560,20 +610,12 @@ int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
>>
>> r = device__register(&vpci->dev_hdr);
>> if (r < 0)
>> - goto free_msix_mmio;
>> + return r;
>>
>> /* save the IRQ that device__register() has allocated */
>> vpci->legacy_irq_line = vpci->pci_hdr.irq_line;
>>
>> return 0;
>> -
>> -free_msix_mmio:
>> - kvm__deregister_mmio(kvm, msix_io_block);
>> -free_mmio:
>> - kvm__deregister_mmio(kvm, mmio_addr);
>> -free_ioport:
>> - ioport__unregister(kvm, port_addr);
>> - return r;
>> }
>>
>> int virtio_pci__reset(struct kvm *kvm, struct virtio_device *vdev)
