[Qemu-devel] [PATCH v6 4/5] PC: add hpet compat to trace compatability version

[Liu Ping Fan <qemulist@gmail.com>]

For guest bug compat, we need to limit hpet's intcap on IRQ2
for pc-q35-1.7 and earlier. We use hpet's compat property to
indicate the PC version.

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>

diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index c6042c7..90f1ea4 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -346,6 +346,10 @@ static QEMUMachine pc_i440fx_machine_v1_7 = {
     .alias = "pc",
     .init = pc_init_pci,
     .is_default = 1,
+    .compat_props = (GlobalProperty[]) {
+        PC_COMPAT_1_7,
+        { /* end of list */ }
+    },
 };
 
 #define PC_I440FX_1_6_MACHINE_OPTIONS PC_I440FX_MACHINE_OPTIONS
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index ca84e1c..569f946 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -270,6 +270,10 @@ static QEMUMachine pc_q35_machine_v1_7 = {
     .name = "pc-q35-1.7",
     .alias = "q35",
     .init = pc_q35_init,
+    .compat_props = (GlobalProperty[]) {
+        PC_COMPAT_1_7,
+        { /* end of list */ }
+    },
 };
 
 #define PC_Q35_1_6_MACHINE_OPTIONS PC_Q35_MACHINE_OPTIONS
diff --git a/hw/timer/hpet.c b/hw/timer/hpet.c
index 69ce587..3cbe71e 100644
--- a/hw/timer/hpet.c
+++ b/hw/timer/hpet.c
@@ -76,6 +76,7 @@ typedef struct HPETState {
     qemu_irq pit_enabled;
     uint8_t num_timers;
     uint32_t intcap;
+    uint8_t compat;
     HPETTimer timer[HPET_MAX_TIMERS];
 
     /* Memory-mapped, software visible registers */
@@ -757,6 +758,7 @@ static Property hpet_device_properties[] = {
     DEFINE_PROP_UINT8("timers", HPETState, num_timers, HPET_MIN_TIMERS),
     DEFINE_PROP_BIT("msi", HPETState, flags, HPET_MSI_SUPPORT, false),
     DEFINE_PROP_UINT32("intcap", HPETState, intcap, 0),
+    DEFINE_PROP_UINT8("compat", HPETState, compat, 0),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 9b2ddc4..80aa7bd 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -225,7 +225,15 @@ void pvpanic_init(ISABus *bus);
 
 int e820_add_entry(uint64_t, uint64_t, uint32_t);
 
+#define PC_COMPAT_1_7 \
+        {\
+            .driver   = "hpet",\
+            .property = "compat",\
+            .value    = stringify(1),\
+        }
+
 #define PC_COMPAT_1_6 \
+        PC_COMPAT_1_7, \
         {\
             .driver   = "e1000",\
             .property = "mitigation",\