target-i386: use memory API to implement SMRAM

Remove cpu_smm_register and cpu_smm_update.  Instead, each CPU
address space gets an extra region which is an alias of
/machine/smram.  This extra region is enabled or disabled
as the CPU enters/exits SMM.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

4 files changed, 16 insertions, 73 deletions

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 2baff4a660..3f0d435da9 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -164,27 +164,6 @@ uint64_t cpu_get_tsc(CPUX86State *env)
     return cpu_get_ticks();
 }
 
-/* SMM support */
-
-static cpu_set_smm_t smm_set;
-static void *smm_arg;
-
-void cpu_smm_register(cpu_set_smm_t callback, void *arg)
-{
-    assert(smm_set == NULL);
-    assert(smm_arg == NULL);
-    smm_set = callback;
-    smm_arg = arg;
-}
-
-void cpu_smm_update(CPUX86State *env)
-{
-    if (smm_set && smm_arg && CPU(x86_env_get_cpu(env)) == first_cpu) {
-        smm_set(!!(env->hflags & HF_SMM_MASK), smm_arg);
-    }
-}
-
-
 /* IRQ handling */
 int cpu_get_pic_interrupt(CPUX86State *env)
 {
diff --git a/hw/pci-host/pam.c b/hw/pci-host/pam.c
index 8272de3f28..99d7af97e7 100644
--- a/hw/pci-host/pam.c
+++ b/hw/pci-host/pam.c
@@ -31,26 +31,12 @@
 #include "sysemu/sysemu.h"
 #include "hw/pci-host/pam.h"
 
-void smram_update(MemoryRegion *smram_region, uint8_t smram,
-                  uint8_t smm_enabled)
+void smram_update(MemoryRegion *smram_region, uint8_t smram)
 {
-    bool smram_enabled;
-
-    smram_enabled = ((smm_enabled && (smram & SMRAM_G_SMRAME)) ||
-                        (smram & SMRAM_D_OPEN));
+    bool smram_enabled = (smram & SMRAM_D_OPEN);
     memory_region_set_enabled(smram_region, !smram_enabled);
 }
 
-void smram_set_smm(uint8_t *host_smm_enabled, int smm, uint8_t smram,
-                   MemoryRegion *smram_region)
-{
-    uint8_t smm_enabled = (smm != 0);
-    if (*host_smm_enabled != smm_enabled) {
-        *host_smm_enabled = smm_enabled;
-        smram_update(smram_region, smram, *host_smm_enabled);
-    }
-}
-
 void init_pam(DeviceState *dev, MemoryRegion *ram_memory,
               MemoryRegion *system_memory, MemoryRegion *pci_address_space,
               PAMMemoryRegion *mem, uint32_t start, uint32_t size)
diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
index 0e439c5d52..a91ad73705 100644
--- a/hw/pci-host/piix.c
+++ b/hw/pci-host/piix.c
@@ -106,7 +106,6 @@ struct PCII440FXState {
     PAMMemoryRegion pam_regions[13];
     MemoryRegion smram_region;
     MemoryRegion smram, low_smram;
-    uint8_t smm_enabled;
 };
 
 
@@ -139,23 +138,12 @@ static void i440fx_update_memory_mappings(PCII440FXState *d)
         pam_update(&d->pam_regions[i], i,
                    pd->config[I440FX_PAM + ((i + 1) / 2)]);
     }
-    smram_update(&d->smram_region, pd->config[I440FX_SMRAM], d->smm_enabled);
+    smram_update(&d->smram_region, pd->config[I440FX_SMRAM]);
     memory_region_set_enabled(&d->smram,
                               pd->config[I440FX_SMRAM] & SMRAM_G_SMRAME);
     memory_region_transaction_commit();
 }
 
-static void i440fx_set_smm(int val, void *arg)
-{
-    PCII440FXState *d = arg;
-    PCIDevice *pd = PCI_DEVICE(d);
-
-    memory_region_transaction_begin();
-    smram_set_smm(&d->smm_enabled, val, pd->config[I440FX_SMRAM],
-                  &d->smram_region);
-    memory_region_transaction_commit();
-}
-
 
 static void i440fx_write_config(PCIDevice *dev,
                                 uint32_t address, uint32_t val, int len)
@@ -175,12 +163,13 @@ static int i440fx_load_old(QEMUFile* f, void *opaque, int version_id)
     PCII440FXState *d = opaque;
     PCIDevice *pd = PCI_DEVICE(d);
     int ret, i;
+    uint8_t smm_enabled;
 
     ret = pci_device_load(pd, f);
     if (ret < 0)
         return ret;
     i440fx_update_memory_mappings(d);
-    qemu_get_8s(f, &d->smm_enabled);
+    qemu_get_8s(f, &smm_enabled);
 
     if (version_id == 2) {
         for (i = 0; i < PIIX_NUM_PIRQS; i++) {
@@ -208,7 +197,10 @@ static const VMStateDescription vmstate_i440fx = {
     .post_load = i440fx_post_load,
     .fields = (VMStateField[]) {
         VMSTATE_PCI_DEVICE(parent_obj, PCII440FXState),
-        VMSTATE_UINT8(smm_enabled, PCII440FXState),
+        /* Used to be smm_enabled, which was basically always zero because
+         * SeaBIOS hardly uses SMM.  SMRAM is now handled by CPU code.
+         */
+        VMSTATE_UNUSED(1),
         VMSTATE_END_OF_LIST()
     }
 };
@@ -300,11 +292,7 @@ static void i440fx_pcihost_realize(DeviceState *dev, Error **errp)
 
 static void i440fx_realize(PCIDevice *dev, Error **errp)
 {
-    PCII440FXState *d = I440FX_PCI_DEVICE(dev);
-
     dev->config[I440FX_SMRAM] = 0x02;
-
-    cpu_smm_register(&i440fx_set_smm, d);
 }
 
 PCIBus *i440fx_init(PCII440FXState **pi440fx_state,
@@ -360,7 +348,7 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state,
     memory_region_init(&f->smram, OBJECT(d), "smram", 1ull << 32);
     memory_region_set_enabled(&f->smram, true);
     memory_region_init_alias(&f->low_smram, OBJECT(d), "smram-low",
-                             f->system_memory, 0xa0000, 0x20000);
+                             f->ram_memory, 0xa0000, 0x20000);
     memory_region_set_enabled(&f->low_smram, true);
     memory_region_add_subregion(&f->smram, 0xa0000, &f->low_smram);
     object_property_add_const_link(qdev_get_machine(), "smram",
diff --git a/hw/pci-host/q35.c b/hw/pci-host/q35.c
index db4d871908..eefa199335 100644
--- a/hw/pci-host/q35.c
+++ b/hw/pci-host/q35.c
@@ -268,24 +268,12 @@ static void mch_update_smram(MCHPCIState *mch)
     PCIDevice *pd = PCI_DEVICE(mch);
 
     memory_region_transaction_begin();
-    smram_update(&mch->smram_region, pd->config[MCH_HOST_BRIDGE_SMRAM],
-                    mch->smm_enabled);
+    smram_update(&mch->smram_region, pd->config[MCH_HOST_BRIDGE_SMRAM]);
     memory_region_set_enabled(&mch->smram,
                               pd->config[MCH_HOST_BRIDGE_SMRAM] & SMRAM_G_SMRAME);
     memory_region_transaction_commit();
 }
 
-static void mch_set_smm(int smm, void *arg)
-{
-    MCHPCIState *mch = arg;
-    PCIDevice *pd = PCI_DEVICE(mch);
-
-    memory_region_transaction_begin();
-    smram_set_smm(&mch->smm_enabled, smm, pd->config[MCH_HOST_BRIDGE_SMRAM],
-                    &mch->smram_region);
-    memory_region_transaction_commit();
-}
-
 static void mch_write_config(PCIDevice *d,
                               uint32_t address, uint32_t val, int len)
 {
@@ -331,7 +319,10 @@ static const VMStateDescription vmstate_mch = {
     .post_load = mch_post_load,
     .fields = (VMStateField[]) {
         VMSTATE_PCI_DEVICE(parent_obj, MCHPCIState),
-        VMSTATE_UINT8(smm_enabled, MCHPCIState),
+        /* Used to be smm_enabled, which was basically always zero because
+         * SeaBIOS hardly uses SMM.  SMRAM is now handled by CPU code.
+         */
+        VMSTATE_UNUSED(1),
         VMSTATE_END_OF_LIST()
     }
 };
@@ -402,7 +393,6 @@ static void mch_realize(PCIDevice *d, Error **errp)
                            mch->pci_address_space);
 
     /* if *disabled* show SMRAM to all CPUs */
-    cpu_smm_register(&mch_set_smm, mch);
     memory_region_init_alias(&mch->smram_region, OBJECT(mch), "smram-region",
                              mch->pci_address_space, 0xa0000, 0x20000);
     memory_region_add_subregion_overlap(mch->system_memory, 0xa0000,
@@ -413,7 +403,7 @@ static void mch_realize(PCIDevice *d, Error **errp)
     memory_region_init(&mch->smram, OBJECT(mch), "smram", 1ull << 32);
     memory_region_set_enabled(&mch->smram, true);
     memory_region_init_alias(&mch->low_smram, OBJECT(mch), "smram-low",
-                             mch->system_memory, 0xa0000, 0x20000);
+                             mch->ram_memory, 0xa0000, 0x20000);
     memory_region_set_enabled(&mch->low_smram, true);
     memory_region_add_subregion(&mch->smram, 0xa0000, &mch->low_smram);
     object_property_add_const_link(qdev_get_machine(), "smram",