Re: [RFC PATCH v2 42/44] hw/i386: add a flag to disable init/sipi delivery mode of interrupt

[Gerd Hoffmann]

  Hi,

>  ioapic_init_gsi(gsi_state, "machine", x86ms->eoi_intercept_unsupported,
> -x86ms->smi_unsupported);
> +x86ms->smi_unsupported, x86ms->init_sipi_unsupported);

Hmm, why add three different switches here?  I suspect these would all
be used together anyway?  So maybe just add a "tdx mode" to the ioapic?
Or maybe better a "confidential-computing" mode, as I guess amd will
have similar requirements for similar reasons?

thanks,
  Gerd

[RFC PATCH v2 42/44] hw/i386: add a flag to disable init/sipi delivery mode of interrupt

[isaku . yamahata]

From: Isaku Yamahata 

Add a new flag to X86Machine to disallow INIT/SIPI delivery mode of
interrupt and pass it to ioapic creation so that ioapic disallows INIT/SIPI
delivery mode.

Signed-off-by: Isaku Yamahata 
---
 hw/i386/microvm.c |  4 ++--
 hw/i386/pc_piix.c |  2 +-
 hw/i386/pc_q35.c  |  2 +-
 hw/i386/x86.c | 11 +--
 include/hw/i386/x86.h |  7 +--
 5 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
index 7504324891..c790adecfb 100644
--- a/hw/i386/microvm.c
+++ b/hw/i386/microvm.c
@@ -176,11 +176,11 @@ static void microvm_devices_init(MicrovmMachineState *mms)
 isa_bus_irqs(isa_bus, x86ms->gsi);
 
 ioapic_init_gsi(gsi_state, "machine", x86ms->eoi_intercept_unsupported,
-x86ms->smi_unsupported);
+x86ms->smi_unsupported, x86ms->init_sipi_unsupported);
 if (ioapics > 1) {
 x86ms->ioapic2 = ioapic_init_secondary(
 gsi_state, x86ms->eoi_intercept_unsupported,
-x86ms->smi_unsupported);
+x86ms->smi_unsupported, x86ms->init_sipi_unsupported);
 }
 
 kvmclock_create(true);
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 0958035bf8..940cd0f47b 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -224,7 +224,7 @@ static void pc_init1(MachineState *machine,
 
 if (pcmc->pci_enabled) {
 ioapic_init_gsi(gsi_state, "i440fx", x86ms->eoi_intercept_unsupported,
-x86ms->smi_unsupported);
+x86ms->smi_unsupported, x86ms->init_sipi_unsupported);
 }
 
 if (tcg_enabled()) {
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 1ab8a6a78b..8f677ec136 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -257,7 +257,7 @@ static void pc_q35_init(MachineState *machine)
 
 if (pcmc->pci_enabled) {
 ioapic_init_gsi(gsi_state, "q35", x86ms->eoi_intercept_unsupported,
-x86ms->smi_unsupported);
+x86ms->smi_unsupported, x86ms->init_sipi_unsupported);
 }
 
 if (tcg_enabled()) {
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 3dc36e3590..24af05c313 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -610,7 +610,8 @@ void gsi_handler(void *opaque, int n, int level)
 
 void ioapic_init_gsi(GSIState *gsi_state, const char *parent_name,
  bool level_trigger_unsupported,
- bool smi_unsupported)
+ bool smi_unsupported,
+ bool init_sipi_unsupported)
 {
 DeviceState *dev;
 SysBusDevice *d;
@@ -628,6 +629,8 @@ void ioapic_init_gsi(GSIState *gsi_state, const char 
*parent_name,
  level_trigger_unsupported, NULL);
 object_property_set_bool(OBJECT(dev), "smi_unsupported",
  smi_unsupported, NULL);
+object_property_set_bool(OBJECT(dev), "init_sipi_unsupported",
+ init_sipi_unsupported, NULL);
 d = SYS_BUS_DEVICE(dev);
 sysbus_realize_and_unref(d, &error_fatal);
 sysbus_mmio_map(d, 0, IO_APIC_DEFAULT_ADDRESS);
@@ -639,7 +642,8 @@ void ioapic_init_gsi(GSIState *gsi_state, const char 
*parent_name,
 
 DeviceState *ioapic_init_secondary(GSIState *gsi_state,
bool level_trigger_unsupported,
-   bool smi_unsupported)
+   bool smi_unsupported,
+   bool init_sipi_unsupported)
 {
 DeviceState *dev;
 SysBusDevice *d;
@@ -650,6 +654,8 @@ DeviceState *ioapic_init_secondary(GSIState *gsi_state,
  level_trigger_unsupported, NULL);
 object_property_set_bool(OBJECT(dev), "smi_unsupported",
  smi_unsupported, NULL);
+object_property_set_bool(OBJECT(dev), "init_sipi_unsupported",
+ init_sipi_unsupported, NULL);
 d = SYS_BUS_DEVICE(dev);
 sysbus_realize_and_unref(d, &error_fatal);
 sysbus_mmio_map(d, 0, IO_APIC_SECONDARY_ADDRESS);
@@ -1325,6 +1331,7 @@ static void x86_machine_initfn(Object *obj)
 x86ms->bus_lock_ratelimit = 0;
 x86ms->eoi_intercept_unsupported = false;
 x86ms->smi_unsupported = false;
+x86ms->init_sipi_unsupported = false;
 
 object_property_add_str(obj, "kvm-type",
 x86_get_kvm_type, x86_set_kvm_type);
diff --git a/include/hw/i386/x86.h b/include/hw/i386/x86.h
index 3d1d74d171..bca8c2b57d 100644
--- a/include/hw/i386/x86.h
+++ b/include/hw/i386/x86.h
@@ -65,6 +65,7 @@ struct X86MachineState {
 uint16_t boot_cpus;
 bool eoi_intercept_unsupported;
 bool smi_unsupported;
+bool init_sipi_unsupported;
 
 OnOffAuto smm;
 OnOffAuto acpi;
@@ -143,9 +144,11 @@ qemu_irq x86_allocate_cpu_irq(void);
 void gsi_handler(void *opaque, int n, int level);
 void ioapic_init_gsi(GSIState *gsi_state, const char *parent_name,