diff options
| author | Marc Zyngier <maz@kernel.org> | 2021-08-25 18:19:27 +0100 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2021-08-25 18:33:39 +0100 |
| commit | c247b4892fd1b05f845b5dfeb914ff2c06f64e64 (patch) | |
| tree | ade2d170ccdba1d3bc323121e266b63b57f2c4db | |
| parent | 25c1dc6c4942ff0949c08780fcad6b324fec6bf7 (diff) | |
| download | kvmtool-msix-fixes.tar.gz | |
virtio/pci: Size the MSI-X bar according to the number of MSI-Xmsix-fixes
Since 45d3b59e8c45 ("kvm tools: Increase amount of possible interrupts
per PCI device"), the number of MSI-S has gone from 4 to 33.
However, the corresponding storage hasn't been upgraded, and writing
to the MSI-X table is a pretty risky business. Now that the Linux
kernel writes to *all* MSI-X entries before doing anything else
with the device, kvmtool dies a horrible death.
Fix it by properly defining the size of the MSI-X bar, and make
Linux great again.
Signed-off-by: Marc Zyngier <maz@kernel.org>
| -rw-r--r-- | virtio/pci.c | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/virtio/pci.c b/virtio/pci.c index eb91f512..726146fc 100644 --- a/virtio/pci.c +++ b/virtio/pci.c @@ -7,6 +7,7 @@ #include "kvm/irq.h" #include "kvm/virtio.h" #include "kvm/ioeventfd.h" +#include "kvm/util.h" #include <sys/ioctl.h> #include <linux/virtio_pci.h> @@ -14,6 +15,13 @@ #include <assert.h> #include <string.h> +#define ALIGN_UP(x, s) ALIGN((x) + (s) - 1, (s)) +#define VIRTIO_NR_MSIX (VIRTIO_PCI_MAX_VQ + VIRTIO_PCI_MAX_CONFIG) +#define VIRTIO_MSIX_TABLE_SIZE (VIRTIO_NR_MSIX * 16) +#define VIRTIO_MSIX_PBA_SIZE (ALIGN_UP(VIRTIO_MSIX_TABLE_SIZE, 64) / 8) +#define VIRTIO_MSIX_BAR_SIZE (1UL << fls_long(VIRTIO_MSIX_TABLE_SIZE + \ + VIRTIO_MSIX_PBA_SIZE)) + static u16 virtio_pci__port_addr(struct virtio_pci *vpci) { return pci__bar_address(&vpci->pci_hdr, 0); @@ -336,15 +344,20 @@ static void virtio_pci__msix_mmio_callback(struct kvm_cpu *vcpu, int vecnum; size_t offset; - if (addr > msix_io_addr + PCI_IO_SIZE) { + if (addr > msix_io_addr + VIRTIO_MSIX_TABLE_SIZE) { + /* Read access to PBA */ if (is_write) return; - table = (struct msix_table *)&vpci->msix_pba; - offset = addr - (msix_io_addr + PCI_IO_SIZE); - } else { - table = vpci->msix_table; - offset = addr - msix_io_addr; + offset = addr - (msix_io_addr + VIRTIO_MSIX_TABLE_SIZE); + if ((offset + len) > sizeof (vpci->msix_pba)) + return; + memcpy(data, (void *)&vpci->msix_pba + offset, len); + return; } + + table = vpci->msix_table; + offset = addr - msix_io_addr; + vecnum = offset / sizeof(struct msix_table); offset = offset % sizeof(struct msix_table); @@ -520,7 +533,7 @@ int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev, port_addr = pci_get_io_port_block(PCI_IO_SIZE); mmio_addr = pci_get_mmio_block(PCI_IO_SIZE); - msix_io_block = pci_get_mmio_block(PCI_IO_SIZE * 2); + msix_io_block = pci_get_mmio_block(VIRTIO_MSIX_BAR_SIZE); vpci->pci_hdr = (struct pci_device_header) { .vendor_id = cpu_to_le16(PCI_VENDOR_ID_REDHAT_QUMRANET), @@ -543,7 +556,7 @@ int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev, .capabilities = (void *)&vpci->pci_hdr.msix - (void *)&vpci->pci_hdr, .bar_size[0] = cpu_to_le32(PCI_IO_SIZE), .bar_size[1] = cpu_to_le32(PCI_IO_SIZE), - .bar_size[2] = cpu_to_le32(PCI_IO_SIZE*2), + .bar_size[2] = cpu_to_le32(VIRTIO_MSIX_BAR_SIZE), }; r = pci__register_bar_regions(kvm, &vpci->pci_hdr, |