From: Jason Wang Date: Thu, 23 Apr 2015 06:21:49 +0000 (+0800) Subject: pci: remove hard-coded bar size in msix_init_exclusive_bar() X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=a0ccd2123ee2f83a1f081e4c39013c3316f9ec7a;p=qmiga%2Fqemu.git pci: remove hard-coded bar size in msix_init_exclusive_bar() This patch lets msix_init_exclusive_bar() can calculate the bar and pba size based on the number of MSI-X vectors other than using a hard-coded limit 4096. This is needed to allow device to have more than 128 MSI_X vectors. To keep migration compatibility, keep using 4096 as bar size and 2048 for pba offset. Notes: We don't care about the case that using vectors > 128 for legacy machine type. Since we limit the queue max to 64, so vectors >= 65 is meaningless. Virtio device will be the first user for this. Cc: Keith Busch Cc: Kevin Wolf Cc: Stefan Hajnoczi Cc: Michael S. Tsirkin Signed-off-by: Jason Wang Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- diff --git a/hw/pci/msix.c b/hw/pci/msix.c index 24de2605fb..f8748cfe1d 100644 --- a/hw/pci/msix.c +++ b/hw/pci/msix.c @@ -295,29 +295,37 @@ int msix_init_exclusive_bar(PCIDevice *dev, unsigned short nentries, { int ret; char *name; + uint32_t bar_size = 4096; + uint32_t bar_pba_offset = bar_size / 2; + uint32_t bar_pba_size = (nentries / 8 + 1) * 8; /* * Migration compatibility dictates that this remains a 4k * BAR with the vector table in the lower half and PBA in - * the upper half. Do not use these elsewhere! + * the upper half for nentries which is lower or equal to 128. + * No need to care about using more than 65 entries for legacy + * machine types who has at most 64 queues. */ -#define MSIX_EXCLUSIVE_BAR_SIZE 4096 -#define MSIX_EXCLUSIVE_BAR_TABLE_OFFSET 0 -#define MSIX_EXCLUSIVE_BAR_PBA_OFFSET (MSIX_EXCLUSIVE_BAR_SIZE / 2) -#define MSIX_EXCLUSIVE_CAP_OFFSET 0 + if (nentries * PCI_MSIX_ENTRY_SIZE > bar_pba_offset) { + bar_pba_offset = nentries * PCI_MSIX_ENTRY_SIZE; + } - if (nentries * PCI_MSIX_ENTRY_SIZE > MSIX_EXCLUSIVE_BAR_PBA_OFFSET) { - return -EINVAL; + if (bar_pba_offset + bar_pba_size > 4096) { + bar_size = bar_pba_offset + bar_pba_size; + } + + if (bar_size & (bar_size - 1)) { + bar_size = 1 << qemu_fls(bar_size); } name = g_strdup_printf("%s-msix", dev->name); - memory_region_init(&dev->msix_exclusive_bar, OBJECT(dev), name, MSIX_EXCLUSIVE_BAR_SIZE); + memory_region_init(&dev->msix_exclusive_bar, OBJECT(dev), name, bar_size); g_free(name); ret = msix_init(dev, nentries, &dev->msix_exclusive_bar, bar_nr, - MSIX_EXCLUSIVE_BAR_TABLE_OFFSET, &dev->msix_exclusive_bar, - bar_nr, MSIX_EXCLUSIVE_BAR_PBA_OFFSET, - MSIX_EXCLUSIVE_CAP_OFFSET); + 0, &dev->msix_exclusive_bar, + bar_nr, bar_pba_offset, + 0); if (ret) { return ret; }