xen/pass-through: correctly deal with RW1C bits

Introduce yet another mask for them, so that the generic routine can
handle them, at once rendering xen_pt_pmcsr_reg_write() superfluous.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

hw/xen/xen_pt.h

@@ -113,6 +113,8 @@ struct XenPTRegInfo {
     uint32_t res_mask;
     /* reg read only field mask (ON:RO/ROS, OFF:other) */
     uint32_t ro_mask;
+    /* reg read/write-1-clear field mask (ON:RW1C/RW1CS, OFF:other) */
+    uint32_t rw1c_mask;
     /* reg emulate field mask (ON:emu, OFF:passthrough) */
     uint32_t emu_mask;
     xen_pt_conf_reg_init init;

hw/xen/xen_pt_config_init.c

@@ -179,7 +179,8 @@ static int xen_pt_byte_reg_write(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
     *data = XEN_PT_MERGE_VALUE(*val, *data, writable_mask);
 
     /* create value for writing to I/O device register */
-    *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
+    *val = XEN_PT_MERGE_VALUE(*val, dev_value & ~reg->rw1c_mask,
+                              throughable_mask);
 
     return 0;
 }
@@ -197,7 +198,8 @@ static int xen_pt_word_reg_write(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
     *data = XEN_PT_MERGE_VALUE(*val, *data, writable_mask);
 
     /* create value for writing to I/O device register */
-    *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
+    *val = XEN_PT_MERGE_VALUE(*val, dev_value & ~reg->rw1c_mask,
+                              throughable_mask);
 
     return 0;
 }
@@ -215,7 +217,8 @@ static int xen_pt_long_reg_write(XenPCIPassthroughState *s, XenPTReg *cfg_entry,
     *data = XEN_PT_MERGE_VALUE(*val, *data, writable_mask);
 
     /* create value for writing to I/O device register */
-    *val = XEN_PT_MERGE_VALUE(*val, dev_value, throughable_mask);
+    *val = XEN_PT_MERGE_VALUE(*val, dev_value & ~reg->rw1c_mask,
+                              throughable_mask);
 
     return 0;
 }
@@ -633,6 +636,7 @@ static XenPTRegInfo xen_pt_emu_reg_header0[] = {
         .init_val   = 0x0000,
         .res_mask   = 0x0007,
         .ro_mask    = 0x06F8,
+        .rw1c_mask  = 0xF900,
         .emu_mask   = 0x0010,
         .init       = xen_pt_status_reg_init,
         .u.w.read   = xen_pt_word_reg_read,
@@ -944,6 +948,7 @@ static XenPTRegInfo xen_pt_emu_reg_pcie[] = {
         .size       = 2,
         .res_mask   = 0xFFC0,
         .ro_mask    = 0x0030,
+        .rw1c_mask  = 0x000F,
         .init       = xen_pt_common_reg_init,
         .u.w.read   = xen_pt_word_reg_read,
         .u.w.write  = xen_pt_word_reg_write,
@@ -964,6 +969,7 @@ static XenPTRegInfo xen_pt_emu_reg_pcie[] = {
         .offset     = PCI_EXP_LNKSTA,
         .size       = 2,
         .ro_mask    = 0x3FFF,
+        .rw1c_mask  = 0xC000,
         .init       = xen_pt_common_reg_init,
         .u.w.read   = xen_pt_word_reg_read,
         .u.w.write  = xen_pt_word_reg_write,
@@ -1000,27 +1006,6 @@ static XenPTRegInfo xen_pt_emu_reg_pcie[] = {
  * Power Management Capability
  */
 
-/* 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 writable_mask = 0;
-    uint16_t throughable_mask = get_throughable_mask(s, reg, valid_mask);
-    uint16_t *data = cfg_entry->ptr.half_word;
-
-    /* modify emulate register */
-    writable_mask = reg->emu_mask & ~reg->ro_mask & valid_mask;
-    *data = XEN_PT_MERGE_VALUE(*val, *data, writable_mask);
-
-    /* create value for writing to I/O device register */
-    *val = XEN_PT_MERGE_VALUE(*val, dev_value & ~PCI_PM_CTRL_PME_STATUS,
-                              throughable_mask);
-
-    return 0;
-}
-
 /* Power Management Capability reg static information table */
 static XenPTRegInfo xen_pt_emu_reg_pm[] = {
     /* Next Pointer reg */
@@ -1051,11 +1036,12 @@ static XenPTRegInfo xen_pt_emu_reg_pm[] = {
         .size       = 2,
         .init_val   = 0x0008,
         .res_mask   = 0x00F0,
-        .ro_mask    = 0xE10C,
+        .ro_mask    = 0x610C,
+        .rw1c_mask  = 0x8000,
         .emu_mask   = 0x810B,
         .init       = xen_pt_common_reg_init,
         .u.w.read   = xen_pt_word_reg_read,
-        .u.w.write  = xen_pt_pmcsr_reg_write,
+        .u.w.write  = xen_pt_word_reg_write,
     },
     {
         .size = 0,