/* * MSI-X device support * * This module includes support for MSI-X in pci devices. * * Author: Michael S. Tsirkin * * Copyright (c) 2009, Red Hat Inc, Michael S. Tsirkin (mst@redhat.com) * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. */ #include "hw.h" #include "msix.h" #include "pci.h" /* Declaration from linux/pci_regs.h */ #define PCI_CAP_ID_MSIX 0x11 /* MSI-X */ #define PCI_MSIX_FLAGS 2 /* Table at lower 11 bits */ #define PCI_MSIX_FLAGS_QSIZE 0x7FF #define PCI_MSIX_FLAGS_ENABLE (1 << 15) #define PCI_MSIX_FLAGS_BIRMASK (7 << 0) /* MSI-X capability structure */ #define MSIX_TABLE_OFFSET 4 #define MSIX_PBA_OFFSET 8 #define MSIX_CAP_LENGTH 12 /* MSI enable bit is in byte 1 in FLAGS register */ #define MSIX_ENABLE_OFFSET (PCI_MSIX_FLAGS + 1) #define MSIX_ENABLE_MASK (PCI_MSIX_FLAGS_ENABLE >> 8) /* MSI-X table format */ #define MSIX_MSG_ADDR 0 #define MSIX_MSG_UPPER_ADDR 4 #define MSIX_MSG_DATA 8 #define MSIX_VECTOR_CTRL 12 #define MSIX_ENTRY_SIZE 16 #define MSIX_VECTOR_MASK 0x1 /* How much space does an MSIX table need. */ /* The spec requires giving the table structure * a 4K aligned region all by itself. Align it to * target pages so that drivers can do passthrough * on the rest of the region. */ #define MSIX_PAGE_SIZE TARGET_PAGE_ALIGN(0x1000) /* Reserve second half of the page for pending bits */ #define MSIX_PAGE_PENDING (MSIX_PAGE_SIZE / 2) #define MSIX_MAX_ENTRIES 32 #ifdef MSIX_DEBUG #define DEBUG(fmt, ...) \ do { \ fprintf(stderr, "%s: " fmt, __func__ , __VA_ARGS__); \ } while (0) #else #define DEBUG(fmt, ...) do { } while(0) #endif /* Flag for interrupt controller to declare MSI-X support */ int msix_supported; /* Add MSI-X capability to the config space for the device. */ /* Given a bar and its size, add MSI-X table on top of it * and fill MSI-X capability in the config space. * Original bar size must be a power of 2 or 0. * New bar size is returned. */ static int msix_add_config(struct PCIDevice *pdev, unsigned short nentries, unsigned bar_nr, unsigned bar_size) { int config_offset; uint8_t *config; uint32_t new_size; if (nentries < 1 || nentries > PCI_MSIX_FLAGS_QSIZE + 1) return -EINVAL; if (bar_size > 0x80000000) return -ENOSPC; /* Add space for MSI-X structures */ if (!bar_size) new_size = MSIX_PAGE_SIZE; else if (bar_size < MSIX_PAGE_SIZE) { bar_size = MSIX_PAGE_SIZE; new_size = MSIX_PAGE_SIZE * 2; } else new_size = bar_size * 2; pdev->msix_bar_size = new_size; config_offset = pci_add_capability(pdev, PCI_CAP_ID_MSIX, MSIX_CAP_LENGTH); if (config_offset < 0) return config_offset; config = pdev->config + config_offset; pci_set_word(config + PCI_MSIX_FLAGS, nentries - 1); /* Table on top of BAR */ pci_set_long(config + MSIX_TABLE_OFFSET, bar_size | bar_nr); /* Pending bits on top of that */ pci_set_long(config + MSIX_PBA_OFFSET, (bar_size + MSIX_PAGE_PENDING) | bar_nr); pdev->msix_cap = config_offset; /* Make flags bit writeable. */ pdev->wmask[config_offset + MSIX_ENABLE_OFFSET] |= MSIX_ENABLE_MASK; return 0; } static void msix_free_irq_entries(PCIDevice *dev) { int vector; for (vector = 0; vector < dev->msix_entries_nr; ++vector) dev->msix_entry_used[vector] = 0; } /* Handle MSI-X capability config write. */ void msix_write_config(PCIDevice *dev, uint32_t addr, uint32_t val, int len) { unsigned enable_pos = dev->msix_cap + MSIX_ENABLE_OFFSET; if (addr + len <= enable_pos || addr > enable_pos) return; if (msix_enabled(dev)) qemu_set_irq(dev->irq[0], 0); } static uint32_t msix_mmio_readl(void *opaque, target_phys_addr_t addr) { PCIDevice *dev = opaque; unsigned int offset = addr & (MSIX_PAGE_SIZE - 1); void *page = dev->msix_table_page; uint32_t val = 0; memcpy(&val, (void *)((char *)page + offset), 4); return val; } static uint32_t msix_mmio_read_unallowed(void *opaque, target_phys_addr_t addr) { fprintf(stderr, "MSI-X: only dword read is allowed!\n"); return 0; } static uint8_t msix_pending_mask(int vector) { return 1 << (vector % 8); } static uint8_t *msix_pending_byte(PCIDevice *dev, int vector) { return dev->msix_table_page + MSIX_PAGE_PENDING + vector / 8; } static int msix_is_pending(PCIDevice *dev, int vector) { return *msix_pending_byte(dev, vector) & msix_pending_mask(vector); } static void msix_set_pending(PCIDevice *dev, int vector) { *msix_pending_byte(dev, vector) |= msix_pending_mask(vector); } 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) { unsigned offset = vector * MSIX_ENTRY_SIZE + MSIX_VECTOR_CTRL; return dev->msix_table_page[offset] & MSIX_VECTOR_MASK; } static void msix_mmio_writel(void *opaque, target_phys_addr_t addr, uint32_t val) { PCIDevice *dev = opaque; unsigned int offset = addr & (MSIX_PAGE_SIZE - 1); int vector = offset / MSIX_ENTRY_SIZE; memcpy(dev->msix_table_page + offset, &val, 4); if (!msix_is_masked(dev, vector) && msix_is_pending(dev, vector)) { msix_clr_pending(dev, vector); msix_notify(dev, vector); } } static void msix_mmio_write_unallowed(void *opaque, target_phys_addr_t addr, uint32_t val) { fprintf(stderr, "MSI-X: only dword write is allowed!\n"); } static CPUWriteMemoryFunc *msix_mmio_write[] = { msix_mmio_write_unallowed, msix_mmio_write_unallowed, msix_mmio_writel }; static CPUReadMemoryFunc *msix_mmio_read[] = { msix_mmio_read_unallowed, msix_mmio_read_unallowed, msix_mmio_readl }; /* Should be called from device's map method. */ void msix_mmio_map(PCIDevice *d, int region_num, uint32_t addr, uint32_t size, int type) { uint8_t *config = d->config + d->msix_cap; uint32_t table = pci_get_long(config + MSIX_TABLE_OFFSET); uint32_t offset = table & ~(MSIX_PAGE_SIZE - 1); /* TODO: for assigned devices, we'll want to make it possible to map * pending bits separately in case they are in a separate bar. */ int table_bir = table & PCI_MSIX_FLAGS_BIRMASK; if (table_bir != region_num) return; if (size <= offset) return; cpu_register_physical_memory(addr + offset, size - offset, d->msix_mmio_index); } /* Initialize the MSI-X structures. Note: if MSI-X is supported, BAR size is * modified, it should be retrieved with msix_bar_size. */ int msix_init(struct PCIDevice *dev, unsigned short nentries, unsigned bar_nr, unsigned bar_size) { int ret; /* Nothing to do if MSI is not supported by interrupt controller */ if (!msix_supported) return -ENOTSUP; if (nentries > MSIX_MAX_ENTRIES) return -EINVAL; dev->msix_entry_used = qemu_mallocz(MSIX_MAX_ENTRIES * sizeof *dev->msix_entry_used); dev->msix_table_page = qemu_mallocz(MSIX_PAGE_SIZE); dev->msix_mmio_index = cpu_register_io_memory(msix_mmio_read, msix_mmio_write, dev); if (dev->msix_mmio_index == -1) { ret = -EBUSY; goto err_index; } dev->msix_entries_nr = nentries; ret = msix_add_config(dev, nentries, bar_nr, bar_size); if (ret) goto err_config; dev->cap_present |= QEMU_PCI_CAP_MSIX; return 0; err_config: cpu_unregister_io_memory(dev->msix_mmio_index); err_index: qemu_free(dev->msix_table_page); dev->msix_table_page = NULL; qemu_free(dev->msix_entry_used); dev->msix_entry_used = NULL; return ret; } /* Clean up resources for the device. */ int msix_uninit(PCIDevice *dev) { if (!(dev->cap_present & QEMU_PCI_CAP_MSIX)) return 0; pci_del_capability(dev, PCI_CAP_ID_MSIX, MSIX_CAP_LENGTH); dev->msix_cap = 0; msix_free_irq_entries(dev); dev->msix_entries_nr = 0; cpu_unregister_io_memory(dev->msix_mmio_index); qemu_free(dev->msix_table_page); dev->msix_table_page = NULL; qemu_free(dev->msix_entry_used); dev->msix_entry_used = NULL; dev->cap_present &= ~QEMU_PCI_CAP_MSIX; return 0; } void msix_save(PCIDevice *dev, QEMUFile *f) { unsigned nentries = (pci_get_word(dev->config + PCI_MSIX_FLAGS) & PCI_MSIX_FLAGS_QSIZE) + 1; qemu_put_buffer(f, dev->msix_table_page, nentries * MSIX_ENTRY_SIZE); qemu_put_buffer(f, dev->msix_table_page + MSIX_PAGE_PENDING, (nentries + 7) / 8); } /* Should be called after restoring the config space. */ void msix_load(PCIDevice *dev, QEMUFile *f) { unsigned n = dev->msix_entries_nr; if (!(dev->cap_present & QEMU_PCI_CAP_MSIX)) { return; } qemu_get_buffer(f, dev->msix_table_page, n * MSIX_ENTRY_SIZE); qemu_get_buffer(f, dev->msix_table_page + MSIX_PAGE_PENDING, (n + 7) / 8); } /* Does device support MSI-X? */ int msix_present(PCIDevice *dev) { return dev->cap_present & QEMU_PCI_CAP_MSIX; } /* Is MSI-X enabled? */ int msix_enabled(PCIDevice *dev) { return (dev->cap_present & QEMU_PCI_CAP_MSIX) && (dev->config[dev->msix_cap + MSIX_ENABLE_OFFSET] & MSIX_ENABLE_MASK); } /* Size of bar where MSI-X table resides, or 0 if MSI-X not supported. */ uint32_t msix_bar_size(PCIDevice *dev) { return (dev->cap_present & QEMU_PCI_CAP_MSIX) ? dev->msix_bar_size : 0; } /* Send an MSI-X message */ void msix_notify(PCIDevice *dev, unsigned vector) { uint8_t *table_entry = dev->msix_table_page + vector * MSIX_ENTRY_SIZE; uint64_t address; uint32_t data; if (vector >= dev->msix_entries_nr || !dev->msix_entry_used[vector]) return; if (msix_is_masked(dev, vector)) { msix_set_pending(dev, vector); return; } address = pci_get_long(table_entry + MSIX_MSG_UPPER_ADDR); address = (address << 32) | pci_get_long(table_entry + MSIX_MSG_ADDR); data = pci_get_long(table_entry + MSIX_MSG_DATA); stl_phys(address, data); } void msix_reset(PCIDevice *dev) { if (!(dev->cap_present & QEMU_PCI_CAP_MSIX)) return; msix_free_irq_entries(dev); dev->config[dev->msix_cap + MSIX_ENABLE_OFFSET] &= MSIX_ENABLE_MASK; memset(dev->msix_table_page, 0, MSIX_PAGE_SIZE); } /* PCI spec suggests that devices make it possible for software to configure * less vectors than supported by the device, but does not specify a standard * mechanism for devices to do so. * * We support this by asking devices to declare vectors software is going to * actually use, and checking this on the notification path. Devices that * don't want to follow the spec suggestion can declare all vectors as used. */ /* Mark vector as used. */ int msix_vector_use(PCIDevice *dev, unsigned vector) { if (vector >= dev->msix_entries_nr) return -EINVAL; dev->msix_entry_used[vector]++; return 0; } /* Mark vector as unused. */ void msix_vector_unuse(PCIDevice *dev, unsigned vector) { if (vector < dev->msix_entries_nr && dev->msix_entry_used[vector]) --dev->msix_entry_used[vector]; }