From ae392c416c69a020226c768d9c3af08b29dd6d96 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 21 Nov 2011 18:57:50 +0200 Subject: [PATCH] msix: avoid mask updates if mask is unchanged Check pending bit only if vector mask status changed. This is not really important for qemu.git but helps fix a bug in qemu-kvm.git. Signed-off-by: Michael S. Tsirkin Signed-off-by: Anthony Liguori --- hw/msix.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) diff --git a/hw/msix.c b/hw/msix.c index 29696016ad..149eed22fb 100644 --- a/hw/msix.c +++ b/hw/msix.c @@ -118,17 +118,25 @@ static void msix_clr_pending(PCIDevice *dev, int vector) *msix_pending_byte(dev, vector) &= ~msix_pending_mask(vector); } -static int msix_is_masked(PCIDevice *dev, int vector) +static bool msix_vector_masked(PCIDevice *dev, int vector, bool fmask) { - unsigned offset = - vector * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL; - return dev->msix_function_masked || - dev->msix_table_page[offset] & PCI_MSIX_ENTRY_CTRL_MASKBIT; + unsigned offset = vector * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL; + return fmask || dev->msix_table_page[offset] & PCI_MSIX_ENTRY_CTRL_MASKBIT; } -static void msix_handle_mask_update(PCIDevice *dev, int vector) +static bool msix_is_masked(PCIDevice *dev, int vector) { - if (!msix_is_masked(dev, vector) && msix_is_pending(dev, vector)) { + return msix_vector_masked(dev, vector, dev->msix_function_masked); +} + +static void msix_handle_mask_update(PCIDevice *dev, int vector, bool was_masked) +{ + bool is_masked = msix_is_masked(dev, vector); + if (is_masked == was_masked) { + return; + } + + if (!is_masked && msix_is_pending(dev, vector)) { msix_clr_pending(dev, vector); msix_notify(dev, vector); } @@ -166,7 +174,8 @@ void msix_write_config(PCIDevice *dev, uint32_t addr, } for (vector = 0; vector < dev->msix_entries_nr; ++vector) { - msix_handle_mask_update(dev, vector); + msix_handle_mask_update(dev, vector, + msix_vector_masked(dev, vector, was_masked)); } } @@ -176,14 +185,16 @@ static void msix_mmio_write(void *opaque, target_phys_addr_t addr, PCIDevice *dev = opaque; unsigned int offset = addr & (MSIX_PAGE_SIZE - 1) & ~0x3; int vector = offset / PCI_MSIX_ENTRY_SIZE; + bool was_masked; /* MSI-X page includes a read-only PBA and a writeable Vector Control. */ if (vector >= dev->msix_entries_nr) { return; } + was_masked = msix_is_masked(dev, vector); pci_set_long(dev->msix_table_page + offset, val); - msix_handle_mask_update(dev, vector); + msix_handle_mask_update(dev, vector, was_masked); } static const MemoryRegionOps msix_mmio_ops = { -- GitLab