Merge remote-tracking branch 'remotes/sstabellini/tags/xen-15-06-02-tag' into staging

XSA 128 129 130 131

# gpg: Signature made Tue Jun  2 16:46:38 2015 BST using RSA key ID 70E1AE90
# gpg: Good signature from "Stefano Stabellini <stefano.stabellini@eu.citrix.com>"

* remotes/sstabellini/tags/xen-15-06-02-tag:
  xen/pt: unknown PCI config space fields should be read-only
  xen/pt: add a few PCI config space field descriptions
  xen/pt: mark reserved bits in PCI config space fields
  xen/pt: mark all PCIe capability bits read-only
  xen/pt: split out calculation of throughable mask in PCI config space handling
  xen/pt: correctly handle PM status bit
  xen/pt: consolidate PM capability emu_mask
  xen/MSI: don't open-code pass-through of enable bit modifications
  xen/MSI-X: limit error messages
  xen: don't allow guest to control MSI mask register
  xen: properly gate host writes of modified PCI CFG contents

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

6 files changed, 217 insertions, 94 deletions

diff --git a/hw/pci/msi.c b/hw/pci/msi.c
index c111dba..f9c0484 100644
--- a/hw/pci/msi.c
+++ b/hw/pci/msi.c
@@ -21,10 +21,6 @@
 #include "hw/pci/msi.h"
 #include "qemu/range.h"
 
-/* Eventually those constants should go to Linux pci_regs.h */
-#define PCI_MSI_PENDING_32      0x10
-#define PCI_MSI_PENDING_64      0x14
-
 /* PCI_MSI_ADDRESS_LO */
 #define PCI_MSI_ADDRESS_LO_MASK         (~0x3)
 
diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
index d095c08..9afcda8 100644
--- a/hw/xen/xen_pt.c
+++ b/hw/xen/xen_pt.c
@@ -234,11 +234,12 @@ static void xen_pt_pci_write_config(PCIDevice *d, uint32_t addr,
     int index = 0;
     XenPTRegGroup *reg_grp_entry = NULL;
     int rc = 0;
-    uint32_t read_val = 0;
+    uint32_t read_val = 0, wb_mask;
     int emul_len = 0;
     XenPTReg *reg_entry = NULL;
     uint32_t find_addr = addr;
     XenPTRegInfo *reg = NULL;
+    bool wp_flag = false;
 
     if (xen_pt_pci_config_access_check(d, addr, len)) {
         return;
@@ -271,10 +272,17 @@ static void xen_pt_pci_write_config(PCIDevice *d, uint32_t addr,
     if (rc < 0) {
         XEN_PT_ERR(d, "pci_read_block failed. return value: %d.\n", rc);
         memset(&read_val, 0xff, len);
+        wb_mask = 0;
+    } else {
+        wb_mask = 0xFFFFFFFF >> ((4 - len) << 3);
     }
 
     /* pass directly to the real device for passthrough type register group */
     if (reg_grp_entry == NULL) {
+        if (!s->permissive) {
+            wb_mask = 0;
+            wp_flag = true;
+        }
         goto out;
     }
 
@@ -295,9 +303,17 @@ static void xen_pt_pci_write_config(PCIDevice *d, uint32_t addr,
             uint32_t real_offset = reg_grp_entry->base_offset + reg->offset;
             uint32_t valid_mask = 0xFFFFFFFF >> ((4 - emul_len) << 3);
             uint8_t *ptr_val = NULL;
+            uint32_t wp_mask = reg->emu_mask | reg->ro_mask;
 
             valid_mask <<= (find_addr - real_offset) << 3;
             ptr_val = (uint8_t *)&val + (real_offset & 3);
+            if (!s->permissive) {
+                wp_mask |= reg->res_mask;
+            }
+            if (wp_mask == (0xFFFFFFFF >> ((4 - reg->size) << 3))) {
+                wb_mask &= ~((wp_mask >> ((find_addr - real_offset) << 3))
+                             << ((len - emul_len) << 3));
+            }
 
             /* do emulation based on register size */
             switch (reg->size) {
@@ -339,6 +355,16 @@ static void xen_pt_pci_write_config(PCIDevice *d, uint32_t addr,
         } else {
             /* nothing to do with passthrough type register,
              * continue to find next byte */
+            if (!s->permissive) {
+                wb_mask &= ~(0xff << ((len - emul_len) << 3));
+                /* Unused BARs will make it here, but we don't want to issue
+                 * warnings for writes to them (bogus writes get dealt with
+                 * above).
+                 */
+                if (index < 0) {
+                    wp_flag = true;
+                }
+            }
             emul_len--;
             find_addr++;
         }
@@ -350,10 +376,26 @@ static void xen_pt_pci_write_config(PCIDevice *d, uint32_t addr,
     memory_region_transaction_commit();
 
 out:
-    if (!(reg && reg->no_wb)) {
+    if (wp_flag && !s->permissive_warned) {
+        s->permissive_warned = true;
+        xen_pt_log(d, "Write-back to unknown field 0x%02x (partially) inhibited (0x%0*x)\n",
+                   addr, len * 2, wb_mask);
+        xen_pt_log(d, "If the device doesn't work, try enabling permissive mode\n");
+        xen_pt_log(d, "(unsafe) and if it helps report the problem to xen-devel\n");
+    }
+    for (index = 0; wb_mask; index += len) {
         /* unknown regs are passed through */
-        rc = xen_host_pci_set_block(&s->real_device, addr,
-                                    (uint8_t *)&val, len);
+        while (!(wb_mask & 0xff)) {
+            index++;
+            wb_mask >>= 8;
+        }
+        len = 0;
+        do {
+            len++;
+            wb_mask >>= 8;
+        } while (wb_mask & 0xff);
+        rc = xen_host_pci_set_block(&s->real_device, addr + index,
+                                    (uint8_t *)&val + index, len);
 
         if (rc < 0) {
             XEN_PT_ERR(d, "pci_write_block failed. return value: %d.\n", rc);
@@ -807,6 +849,7 @@ static void xen_pt_unregister_device(PCIDevice *d)
 
 static Property xen_pci_passthrough_properties[] = {
     DEFINE_PROP_PCI_HOST_DEVADDR("hostaddr", XenPCIPassthroughState, hostaddr),
+    DEFINE_PROP_BOOL("permissive", XenPCIPassthroughState, permissive, false),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/xen/xen_pt.h b/hw/xen/xen_pt.h
index 942dc60..4bba559 100644
--- a/hw/xen/xen_pt.h
+++ b/hw/xen/xen_pt.h
@@ -101,12 +101,12 @@ struct XenPTRegInfo {
     uint32_t offset;
     uint32_t size;
     uint32_t init_val;
+    /* reg reserved field mask (ON:reserved, OFF:defined) */
+    uint32_t res_mask;
     /* reg read only field mask (ON:RO/ROS, OFF:other) */
     uint32_t ro_mask;
     /* reg emulate field mask (ON:emu, OFF:passthrough) */
     uint32_t emu_mask;
-    /* no write back allowed */
-    uint32_t no_wb;
     xen_pt_conf_reg_init init;
     /* read/write function pointer
      * for double_word/word/byte size */
@@ -177,6 +177,7 @@ typedef struct XenPTMSIXEntry {
     uint32_t data;
     uint32_t vector_ctrl;
     bool updated; /* indicate whether MSI ADDR or DATA is updated */
+    bool warned;  /* avoid issuing (bogus) warning more than once */
 } XenPTMSIXEntry;
 typedef struct XenPTMSIX {
     uint32_t ctrl_offset;
@@ -196,6 +197,8 @@ struct XenPCIPassthroughState {
 
     PCIHostDeviceAddress hostaddr;
     bool is_virtfn;
+    bool permissive;
+    bool permissive_warned;
     XenHostPCIDevice real_device;
     XenPTRegion bases[PCI_NUM_REGIONS]; /* Access regions */
     QLIST_HEAD(, XenPTRegGroup) reg_grps;
diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
index 95a51db..f3cf069 100644
--- a/hw/xen/xen_pt_config_init.c
+++ b/hw/xen/xen_pt_config_init.c
@@ -95,6 +95,18 @@ XenPTReg *xen_pt_find_reg(XenPTRegGroup *reg_grp, uint32_t address)
     return NULL;
 }
 
+static uint32_t get_throughable_mask(const XenPCIPassthroughState *s,
+                                     const XenPTRegInfo *reg,
+                                     uint32_t valid_mask)
+{
+    uint32_t throughable_mask = ~(reg->emu_mask | reg->ro_mask);
+
+    if (!s->permissive) {
+        throughable_mask &= ~reg->res_mask;
+    }
+
+    return throughable_mask & valid_mask;
+}
 
 /****************
  * general register functions
@@ -157,14 +169,13 @@ static int xen_pt_byte_reg_write(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
 {
     XenPTRegInfo *reg = cfg_entry->reg;
     uint8_t writable_mask = 0;
-    uint8_t throughable_mask = 0;
+    uint8_t throughable_mask = get_throughable_mask(s, reg, valid_mask);
 
     /* modify emulate register */
     writable_mask = reg->emu_mask & ~reg->ro_mask & valid_mask;
     cfg_entry->data = XEN_PT_MERGE_VALUE(*val, cfg_entry->data, writable_mask);
 
     /* create value for writing to I/O device register */
-    throughable_mask = ~reg->emu_mask & valid_mask;
     *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
 
     return 0;
@@ -175,14 +186,13 @@ static int xen_pt_word_reg_write(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
 {
     XenPTRegInfo *reg = cfg_entry->reg;
     uint16_t writable_mask = 0;
-    uint16_t throughable_mask = 0;
+    uint16_t throughable_mask = get_throughable_mask(s, reg, valid_mask);
 
     /* modify emulate register */
     writable_mask = reg->emu_mask & ~reg->ro_mask & valid_mask;
     cfg_entry->data = XEN_PT_MERGE_VALUE(*val, cfg_entry->data, writable_mask);
 
     /* create value for writing to I/O device register */
-    throughable_mask = ~reg->emu_mask & valid_mask;
     *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
 
     return 0;
@@ -193,14 +203,13 @@ static int xen_pt_long_reg_write(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
 {
     XenPTRegInfo *reg = cfg_entry->reg;
     uint32_t writable_mask = 0;
-    uint32_t throughable_mask = 0;
+    uint32_t throughable_mask = get_throughable_mask(s, reg, valid_mask);
 
     /* modify emulate register */
     writable_mask = reg->emu_mask & ~reg->ro_mask & valid_mask;
     cfg_entry->data = XEN_PT_MERGE_VALUE(*val, cfg_entry->data, writable_mask);
 
     /* create value for writing to I/O device register */
-    throughable_mask = ~reg->emu_mask & valid_mask;
     *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
 
     return 0;
@@ -292,15 +301,13 @@ static int xen_pt_cmd_reg_write(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
 {
     XenPTRegInfo *reg = cfg_entry->reg;
     uint16_t writable_mask = 0;
-    uint16_t throughable_mask = 0;
+    uint16_t throughable_mask = get_throughable_mask(s, reg, valid_mask);
 
     /* modify emulate register */
     writable_mask = ~reg->ro_mask & valid_mask;
     cfg_entry->data = XEN_PT_MERGE_VALUE(*val, cfg_entry->data, writable_mask);
 
     /* create value for writing to I/O device register */
-    throughable_mask = ~reg->emu_mask & valid_mask;
-
     if (*val & PCI_COMMAND_INTX_DISABLE) {
         throughable_mask |= PCI_COMMAND_INTX_DISABLE;
     } else {
@@ -454,7 +461,6 @@ static int xen_pt_bar_reg_write(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
     PCIDevice *d = &s->dev;
     const PCIIORegion *r;
     uint32_t writable_mask = 0;
-    uint32_t throughable_mask = 0;
     uint32_t bar_emu_mask = 0;
     uint32_t bar_ro_mask = 0;
     uint32_t r_size = 0;
@@ -511,8 +517,7 @@ static int xen_pt_bar_reg_write(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
     }
 
     /* create value for writing to I/O device register */
-    throughable_mask = ~bar_emu_mask & valid_mask;
-    *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
+    *val = XEN_PT_MERGE_VALUE(*val, dev_value, 0);
 
     return 0;
 }
@@ -526,9 +531,8 @@ static int xen_pt_exp_rom_bar_reg_write(XenPCIPassthroughState *s,
     XenPTRegion *base = NULL;
     PCIDevice *d = (PCIDevice *)&s->dev;
     uint32_t writable_mask = 0;
-    uint32_t throughable_mask = 0;
+    uint32_t throughable_mask = get_throughable_mask(s, reg, valid_mask);
     pcibus_t r_size = 0;
-    uint32_t bar_emu_mask = 0;
     uint32_t bar_ro_mask = 0;
 
     r_size = d->io_regions[PCI_ROM_SLOT].size;
@@ -537,7 +541,6 @@ static int xen_pt_exp_rom_bar_reg_write(XenPCIPassthroughState *s,
     r_size = xen_pt_get_emul_size(base->bar_flag, r_size);
 
     /* set emulate mask and read-only mask */
-    bar_emu_mask = reg->emu_mask;
     bar_ro_mask = (reg->ro_mask | (r_size - 1)) & ~PCI_ROM_ADDRESS_ENABLE;
 
     /* modify emulate register */
@@ -545,7 +548,6 @@ static int xen_pt_exp_rom_bar_reg_write(XenPCIPassthroughState *s,
     cfg_entry->data = XEN_PT_MERGE_VALUE(*val, cfg_entry->data, writable_mask);
 
     /* create value for writing to I/O device register */
-    throughable_mask = ~bar_emu_mask & valid_mask;
     *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
 
     return 0;
@@ -580,7 +582,7 @@ static XenPTRegInfo xen_pt_emu_reg_header0[] = {
         .offset     = PCI_COMMAND,
         .size       = 2,
         .init_val   = 0x0000,
-        .ro_mask    = 0xF880,
+        .res_mask   = 0xF880,
         .emu_mask   = 0x0743,
         .init       = xen_pt_common_reg_init,
         .u.w.read   = xen_pt_word_reg_read,
@@ -605,7 +607,8 @@ static XenPTRegInfo xen_pt_emu_reg_header0[] = {
         .offset     = PCI_STATUS,
         .size       = 2,
         .init_val   = 0x0000,
-        .ro_mask    = 0x06FF,
+        .res_mask   = 0x0007,
+        .ro_mask    = 0x06F8,
         .emu_mask   = 0x0010,
         .init       = xen_pt_status_reg_init,
         .u.w.read   = xen_pt_word_reg_read,
@@ -755,6 +758,15 @@ static XenPTRegInfo xen_pt_emu_reg_vpd[] = {
         .u.b.write  = xen_pt_byte_reg_write,
     },
     {
+        .offset     = PCI_VPD_ADDR,
+        .size       = 2,
+        .ro_mask    = 0x0003,
+        .emu_mask   = 0x0003,
+        .init       = xen_pt_common_reg_init,
+        .u.w.read   = xen_pt_word_reg_read,
+        .u.w.write  = xen_pt_word_reg_write,
+    },
+    {
         .size = 0,
     },
 };
@@ -873,7 +885,7 @@ static XenPTRegInfo xen_pt_emu_reg_pcie[] = {
         .offset     = PCI_EXP_DEVCAP,
         .size       = 4,
         .init_val   = 0x00000000,
-        .ro_mask    = 0x1FFCFFFF,
+        .ro_mask    = 0xFFFFFFFF,
         .emu_mask   = 0x10000000,
         .init       = xen_pt_common_reg_init,
         .u.dw.read  = xen_pt_long_reg_read,
@@ -890,6 +902,16 @@ static XenPTRegInfo xen_pt_emu_reg_pcie[] = {
         .u.w.read   = xen_pt_word_reg_read,
         .u.w.write  = xen_pt_word_reg_write,
     },
+    /* Device Status reg */
+    {
+        .offset     = PCI_EXP_DEVSTA,
+        .size       = 2,
+        .res_mask   = 0xFFC0,
+        .ro_mask    = 0x0030,
+        .init       = xen_pt_common_reg_init,
+        .u.w.read   = xen_pt_word_reg_read,
+        .u.w.write  = xen_pt_word_reg_write,
+    },
     /* Link Control reg */
     {
         .offset     = PCI_EXP_LNKCTL,
@@ -901,6 +923,15 @@ static XenPTRegInfo xen_pt_emu_reg_pcie[] = {
         .u.w.read   = xen_pt_word_reg_read,
         .u.w.write  = xen_pt_word_reg_write,
     },
+    /* Link Status reg */
+    {
+        .offset     = PCI_EXP_LNKSTA,
+        .size       = 2,
+        .ro_mask    = 0x3FFF,
+        .init       = xen_pt_common_reg_init,
+        .u.w.read   = xen_pt_word_reg_read,
+        .u.w.write  = xen_pt_word_reg_write,
+    },
     /* Device Control 2 reg */
     {
         .offset     = 0x28,
@@ -933,39 +964,22 @@ static XenPTRegInfo xen_pt_emu_reg_pcie[] = {
  * Power Management Capability
  */
 
-/* read Power Management Control/Status register */
-static int xen_pt_pmcsr_reg_read(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
-                                 uint16_t *value, uint16_t valid_mask)
-{
-    XenPTRegInfo *reg = cfg_entry->reg;
-    uint16_t valid_emu_mask = reg->emu_mask;
-
-    valid_emu_mask |= PCI_PM_CTRL_STATE_MASK | PCI_PM_CTRL_NO_SOFT_RESET;
-
-    valid_emu_mask = valid_emu_mask & valid_mask;
-    *value = XEN_PT_MERGE_VALUE(*value, cfg_entry->data, ~valid_emu_mask);
-
-    return 0;
-}
 /* write Power Management Control/Status register */
 static int xen_pt_pmcsr_reg_write(XenPCIPassthroughState *s,
                                   XenPTReg *cfg_entry, uint16_t *val,
                                   uint16_t dev_value, uint16_t valid_mask)
 {
     XenPTRegInfo *reg = cfg_entry->reg;
-    uint16_t emu_mask = reg->emu_mask;
     uint16_t writable_mask = 0;
-    uint16_t throughable_mask = 0;
-
-    emu_mask |= PCI_PM_CTRL_STATE_MASK | PCI_PM_CTRL_NO_SOFT_RESET;
+    uint16_t throughable_mask = get_throughable_mask(s, reg, valid_mask);
 
     /* modify emulate register */
-    writable_mask = emu_mask & ~reg->ro_mask & valid_mask;
+    writable_mask = reg->emu_mask & ~reg->ro_mask & valid_mask;
     cfg_entry->data = XEN_PT_MERGE_VALUE(*val, cfg_entry->data, writable_mask);
 
     /* create value for writing to I/O device register */
-    throughable_mask = ~emu_mask & valid_mask;
-    *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
+    *val = XEN_PT_MERGE_VALUE(*val, dev_value & ~PCI_PM_CTRL_PME_STATUS,
+                              throughable_mask);
 
     return 0;
 }
@@ -999,10 +1013,11 @@ static XenPTRegInfo xen_pt_emu_reg_pm[] = {
         .offset     = PCI_PM_CTRL,
         .size       = 2,
         .init_val   = 0x0008,
-        .ro_mask    = 0xE1FC,
-        .emu_mask   = 0x8100,
+        .res_mask   = 0x00F0,
+        .ro_mask    = 0xE10C,
+        .emu_mask   = 0x810B,
         .init       = xen_pt_common_reg_init,
-        .u.w.read   = xen_pt_pmcsr_reg_read,
+        .u.w.read   = xen_pt_word_reg_read,
         .u.w.write  = xen_pt_pmcsr_reg_write,
     },
     {
@@ -1016,13 +1031,9 @@ static XenPTRegInfo xen_pt_emu_reg_pm[] = {
  */
 
 /* Helper */
-static bool xen_pt_msgdata_check_type(uint32_t offset, uint16_t flags)
-{
-    /* check the offset whether matches the type or not */
-    bool is_32 = (offset == PCI_MSI_DATA_32) && !(flags & PCI_MSI_FLAGS_64BIT);
-    bool is_64 = (offset == PCI_MSI_DATA_64) &&  (flags & PCI_MSI_FLAGS_64BIT);
-    return is_32 || is_64;
-}
+#define xen_pt_msi_check_type(offset, flags, what) \
+        ((offset) == ((flags) & PCI_MSI_FLAGS_64BIT ? \
+                      PCI_MSI_##what##_64 : PCI_MSI_##what##_32))
 
 /* Message Control register */
 static int xen_pt_msgctrl_reg_init(XenPCIPassthroughState *s,
@@ -1056,8 +1067,7 @@ static int xen_pt_msgctrl_reg_write(XenPCIPassthroughState *s,
     XenPTRegInfo *reg = cfg_entry->reg;
     XenPTMSI *msi = s->msi;
     uint16_t writable_mask = 0;
-    uint16_t throughable_mask = 0;
-    uint16_t raw_val;
+    uint16_t throughable_mask = get_throughable_mask(s, reg, valid_mask);
 
     /* Currently no support for multi-vector */
     if (*val & PCI_MSI_FLAGS_QSIZE) {
@@ -1070,12 +1080,10 @@ static int xen_pt_msgctrl_reg_write(XenPCIPassthroughState *s,
     msi->flags |= cfg_entry->data & ~PCI_MSI_FLAGS_ENABLE;
 
     /* create value for writing to I/O device register */
-    raw_val = *val;
-    throughable_mask = ~reg->emu_mask & valid_mask;
     *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
 
     /* update MSI */
-    if (raw_val & PCI_MSI_FLAGS_ENABLE) {
+    if (*val & PCI_MSI_FLAGS_ENABLE) {
         /* setup MSI pirq for the first time */
         if (!msi->initialized) {
             /* Init physical one */
@@ -1103,10 +1111,6 @@ static int xen_pt_msgctrl_reg_write(XenPCIPassthroughState *s,
         xen_pt_msi_disable(s);
     }
 
-    /* pass through MSI_ENABLE bit */
-    *val &= ~PCI_MSI_FLAGS_ENABLE;
-    *val |= raw_val & PCI_MSI_FLAGS_ENABLE;
-
     return 0;
 }
 
@@ -1134,7 +1138,45 @@ static int xen_pt_msgdata_reg_init(XenPCIPassthroughState *s,
     uint32_t offset = reg->offset;
 
     /* check the offset whether matches the type or not */
-    if (xen_pt_msgdata_check_type(offset, flags)) {
+    if (xen_pt_msi_check_type(offset, flags, DATA)) {
+        *data = reg->init_val;
+    } else {
+        *data = XEN_PT_INVALID_REG;
+    }
+    return 0;
+}
+
+/* this function will be called twice (for 32 bit and 64 bit type) */
+/* initialize Mask register */
+static int xen_pt_mask_reg_init(XenPCIPassthroughState *s,
+                                XenPTRegInfo *reg, uint32_t real_offset,
+                                uint32_t *data)
+{
+    uint32_t flags = s->msi->flags;
+
+    /* check the offset whether matches the type or not */
+    if (!(flags & PCI_MSI_FLAGS_MASKBIT)) {
+        *data = XEN_PT_INVALID_REG;
+    } else if (xen_pt_msi_check_type(reg->offset, flags, MASK)) {
+        *data = reg->init_val;
+    } else {
+        *data = XEN_PT_INVALID_REG;
+    }
+    return 0;
+}
+
+/* this function will be called twice (for 32 bit and 64 bit type) */
+/* initialize Pending register */
+static int xen_pt_pending_reg_init(XenPCIPassthroughState *s,
+                                   XenPTRegInfo *reg, uint32_t real_offset,
+                                   uint32_t *data)
+{
+    uint32_t flags = s->msi->flags;
+
+    /* check the offset whether matches the type or not */
+    if (!(flags & PCI_MSI_FLAGS_MASKBIT)) {
+        *data = XEN_PT_INVALID_REG;
+    } else if (xen_pt_msi_check_type(reg->offset, flags, PENDING)) {
         *data = reg->init_val;
     } else {
         *data = XEN_PT_INVALID_REG;
@@ -1149,7 +1191,6 @@ static int xen_pt_msgaddr32_reg_write(XenPCIPassthroughState *s,
 {
     XenPTRegInfo *reg = cfg_entry->reg;
     uint32_t writable_mask = 0;
-    uint32_t throughable_mask = 0;
     uint32_t old_addr = cfg_entry->data;
 
     /* modify emulate register */
@@ -1158,8 +1199,7 @@ static int xen_pt_msgaddr32_reg_write(XenPCIPassthroughState *s,
     s->msi->addr_lo = cfg_entry->data;
 
     /* create value for writing to I/O device register */
-    throughable_mask = ~reg->emu_mask & valid_mask;
-    *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
+    *val = XEN_PT_MERGE_VALUE(*val, dev_value, 0);
 
     /* update MSI */
     if (cfg_entry->data != old_addr) {
@@ -1177,7 +1217,6 @@ static int xen_pt_msgaddr64_reg_write(XenPCIPassthroughState *s,
 {
     XenPTRegInfo *reg = cfg_entry->reg;
     uint32_t writable_mask = 0;
-    uint32_t throughable_mask = 0;
     uint32_t old_addr = cfg_entry->data;
 
     /* check whether the type is 64 bit or not */
@@ -1194,8 +1233,7 @@ static int xen_pt_msgaddr64_reg_write(XenPCIPassthroughState *s,
     s->msi->addr_hi = cfg_entry->data;
 
     /* create value for writing to I/O device register */
-    throughable_mask = ~reg->emu_mask & valid_mask;
-    *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
+    *val = XEN_PT_MERGE_VALUE(*val, dev_value, 0);
 
     /* update MSI */
     if (cfg_entry->data != old_addr) {
@@ -1217,12 +1255,11 @@ static int xen_pt_msgdata_reg_write(XenPCIPassthroughState *s,
     XenPTRegInfo *reg = cfg_entry->reg;
     XenPTMSI *msi = s->msi;
     uint16_t writable_mask = 0;
-    uint16_t throughable_mask = 0;
     uint16_t old_data = cfg_entry->data;
     uint32_t offset = reg->offset;
 
     /* check the offset whether matches the type or not */
-    if (!xen_pt_msgdata_check_type(offset, msi->flags)) {
+    if (!xen_pt_msi_check_type(offset, msi->flags, DATA)) {
         /* exit I/O emulator */
         XEN_PT_ERR(&s->dev, "the offset does not match the 32/64 bit type!\n");
         return -1;
@@ -1235,8 +1272,7 @@ static int xen_pt_msgdata_reg_write(XenPCIPassthroughState *s,
     msi->data = cfg_entry->data;
 
     /* create value for writing to I/O device register */
-    throughable_mask = ~reg->emu_mask & valid_mask;
-    *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
+    *val = XEN_PT_MERGE_VALUE(*val, dev_value, 0);
 
     /* update MSI */
     if (cfg_entry->data != old_data) {
@@ -1266,8 +1302,9 @@ static XenPTRegInfo xen_pt_emu_reg_msi[] = {
         .offset     = PCI_MSI_FLAGS,
         .size       = 2,
         .init_val   = 0x0000,
-        .ro_mask    = 0xFF8E,
-        .emu_mask   = 0x007F,
+        .res_mask   = 0xFE00,
+        .ro_mask    = 0x018E,
+        .emu_mask   = 0x017E,
         .init       = xen_pt_msgctrl_reg_init,
         .u.w.read   = xen_pt_word_reg_read,
         .u.w.write  = xen_pt_msgctrl_reg_write,
@@ -1279,7 +1316,6 @@ static XenPTRegInfo xen_pt_emu_reg_msi[] = {
         .init_val   = 0x00000000,
         .ro_mask    = 0x00000003,
         .emu_mask   = 0xFFFFFFFF,
-        .no_wb      = 1,
         .init       = xen_pt_common_reg_init,
         .u.dw.read  = xen_pt_long_reg_read,
         .u.dw.write = xen_pt_msgaddr32_reg_write,
@@ -1291,7 +1327,6 @@ static XenPTRegInfo xen_pt_emu_reg_msi[] = {
         .init_val   = 0x00000000,
         .ro_mask    = 0x00000000,
         .emu_mask   = 0xFFFFFFFF,
-        .no_wb      = 1,
         .init       = xen_pt_msgaddr64_reg_init,
         .u.dw.read  = xen_pt_long_reg_read,
         .u.dw.write = xen_pt_msgaddr64_reg_write,
@@ -1303,7 +1338,6 @@ static XenPTRegInfo xen_pt_emu_reg_msi[] = {
         .init_val   = 0x0000,
         .ro_mask    = 0x0000,
         .emu_mask   = 0xFFFF,
-        .no_wb      = 1,
         .init       = xen_pt_msgdata_reg_init,
         .u.w.read   = xen_pt_word_reg_read,
         .u.w.write  = xen_pt_msgdata_reg_write,
@@ -1315,11 +1349,54 @@ static XenPTRegInfo xen_pt_emu_reg_msi[] = {
         .init_val   = 0x0000,
         .ro_mask    = 0x0000,
         .emu_mask   = 0xFFFF,
-        .no_wb      = 1,
         .init       = xen_pt_msgdata_reg_init,
         .u.w.read   = xen_pt_word_reg_read,
         .u.w.write  = xen_pt_msgdata_reg_write,
     },
+    /* Mask reg (if PCI_MSI_FLAGS_MASKBIT set, for 32-bit devices) */
+    {
+        .offset     = PCI_MSI_MASK_32,
+        .size       = 4,
+        .init_val   = 0x00000000,
+        .ro_mask    = 0xFFFFFFFF,
+        .emu_mask   = 0xFFFFFFFF,
+        .init       = xen_pt_mask_reg_init,
+        .u.dw.read  = xen_pt_long_reg_read,
+        .u.dw.write = xen_pt_long_reg_write,
+    },
+    /* Mask reg (if PCI_MSI_FLAGS_MASKBIT set, for 64-bit devices) */
+    {
+        .offset     = PCI_MSI_MASK_64,
+        .size       = 4,
+        .init_val   = 0x00000000,
+        .ro_mask    = 0xFFFFFFFF,
+        .emu_mask   = 0xFFFFFFFF,
+        .init       = xen_pt_mask_reg_init,
+        .u.dw.read  = xen_pt_long_reg_read,
+        .u.dw.write = xen_pt_long_reg_write,
+    },
+    /* Pending reg (if PCI_MSI_FLAGS_MASKBIT set, for 32-bit devices) */
+    {
+        .offset     = PCI_MSI_MASK_32 + 4,
+        .size       = 4,
+        .init_val   = 0x00000000,
+        .ro_mask    = 0xFFFFFFFF,
+        .emu_mask   = 0x00000000,
+        .init       = xen_pt_pending_reg_init,
+        .u.dw.read  = xen_pt_long_reg_read,
+        .u.dw.write = xen_pt_long_reg_write,
+    },
+    /* Pending reg (if PCI_MSI_FLAGS_MASKBIT set, for 64-bit devices) */
+    {
+        .offset     = PCI_MSI_MASK_64 + 4,
+        .size       = 4,
+        .init_val   = 0x00000000,
+        .ro_mask    = 0xFFFFFFFF,
+        .emu_mask   = 0x00000000,
+        .init       = xen_pt_pending_reg_init,
+        .u.dw.read  = xen_pt_long_reg_read,
+        .u.dw.write = xen_pt_long_reg_write,
+    },
     {
         .size = 0,
     },
@@ -1358,7 +1435,7 @@ static int xen_pt_msixctrl_reg_write(XenPCIPassthroughState *s,
 {
     XenPTRegInfo *reg = cfg_entry->reg;
     uint16_t writable_mask = 0;
-    uint16_t throughable_mask = 0;
+    uint16_t throughable_mask = get_throughable_mask(s, reg, valid_mask);
     int debug_msix_enabled_old;
 
     /* modify emulate register */
@@ -1366,7 +1443,6 @@ static int xen_pt_msixctrl_reg_write(XenPCIPassthroughState *s,
     cfg_entry->data = XEN_PT_MERGE_VALUE(*val, cfg_entry->data, writable_mask);
 
     /* create value for writing to I/O device register */
-    throughable_mask = ~reg->emu_mask & valid_mask;
     *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
 
     /* update MSI-X */
@@ -1405,7 +1481,8 @@ static XenPTRegInfo xen_pt_emu_reg_msix[] = {
         .offset     = PCI_MSI_FLAGS,
         .size       = 2,
         .init_val   = 0x0000,
-        .ro_mask    = 0x3FFF,
+        .res_mask   = 0x3800,
+        .ro_mask    = 0x07FF,
         .emu_mask   = 0x0000,
         .init       = xen_pt_msixctrl_reg_init,
         .u.w.read   = xen_pt_word_reg_read,
diff --git a/hw/xen/xen_pt_msi.c b/hw/xen/xen_pt_msi.c
index 9ed9321..68db623 100644
--- a/hw/xen/xen_pt_msi.c
+++ b/hw/xen/xen_pt_msi.c
@@ -434,11 +434,10 @@ static void pci_msix_write(void *opaque, hwaddr addr,
     XenPCIPassthroughState *s = opaque;
     XenPTMSIX *msix = s->msix;
     XenPTMSIXEntry *entry;
-    int entry_nr, offset;
+    unsigned int entry_nr, offset;
 
     entry_nr = addr / PCI_MSIX_ENTRY_SIZE;
-    if (entry_nr < 0 || entry_nr >= msix->total_entries) {
-        XEN_PT_ERR(&s->dev, "asked MSI-X entry '%i' invalid!\n", entry_nr);
+    if (entry_nr >= msix->total_entries) {
         return;
     }
     entry = &msix->msix_entry[entry_nr];
@@ -460,8 +459,11 @@ static void pci_msix_write(void *opaque, hwaddr addr,
             + PCI_MSIX_ENTRY_VECTOR_CTRL;
 
         if (msix->enabled && !(*vec_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT)) {
-            XEN_PT_ERR(&s->dev, "Can't update msix entry %d since MSI-X is"
-                       " already enabled.\n", entry_nr);
+            if (!entry->warned) {
+                entry->warned = true;
+                XEN_PT_ERR(&s->dev, "Can't update msix entry %d since MSI-X is"
+                           " already enabled.\n", entry_nr);
+            }
             return;
         }
 
diff --git a/include/hw/pci/pci_regs.h b/include/hw/pci/pci_regs.h
index 56a404b..57e8c80 100644
--- a/include/hw/pci/pci_regs.h
+++ b/include/hw/pci/pci_regs.h
@@ -298,8 +298,10 @@
 #define PCI_MSI_ADDRESS_HI	8	/* Upper 32 bits (if PCI_MSI_FLAGS_64BIT set) */
 #define PCI_MSI_DATA_32		8	/* 16 bits of data for 32-bit devices */
 #define PCI_MSI_MASK_32		12	/* Mask bits register for 32-bit devices */
+#define PCI_MSI_PENDING_32	16	/* Pending bits register for 32-bit devices */
 #define PCI_MSI_DATA_64		12	/* 16 bits of data for 64-bit devices */
 #define PCI_MSI_MASK_64		16	/* Mask bits register for 64-bit devices */
+#define PCI_MSI_PENDING_64	20	/* Pending bits register for 32-bit devices */
 
 /* MSI-X registers */
 #define PCI_MSIX_FLAGS		2