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* [PATCH v3] x86: add etc/phys-bits fw_cfg file
@ 2022-09-22  8:43 Gerd Hoffmann
  2022-09-22  8:55 ` Michael S. Tsirkin
  2022-09-22  9:55 ` Michael S. Tsirkin
  0 siblings, 2 replies; 5+ messages in thread
From: Gerd Hoffmann @ 2022-09-22  8:43 UTC (permalink / raw)
  To: qemu-devel
  Cc: Sergio Lopez, Michael S. Tsirkin, Eduardo Habkost,
	Richard Henderson, Marcelo Tosatti, kvm, Marcel Apfelbaum,
	Paolo Bonzini, Gerd Hoffmann

In case phys bits are functional and can be used by the guest (aka
host-phys-bits=on) add a fw_cfg file carrying the value.  This can
be used by the guest firmware for address space configuration.

This is only enabled for 7.2+ machine types for live migration
compatibility reasons.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/i386/fw_cfg.h     |  1 +
 include/hw/i386/pc.h |  1 +
 hw/i386/fw_cfg.c     | 12 ++++++++++++
 hw/i386/pc.c         |  5 +++++
 hw/i386/pc_piix.c    |  2 ++
 hw/i386/pc_q35.c     |  2 ++
 6 files changed, 23 insertions(+)

diff --git a/hw/i386/fw_cfg.h b/hw/i386/fw_cfg.h
index 275f15c1c5e8..6ff198a6cb85 100644
--- a/hw/i386/fw_cfg.h
+++ b/hw/i386/fw_cfg.h
@@ -26,5 +26,6 @@ FWCfgState *fw_cfg_arch_create(MachineState *ms,
 void fw_cfg_build_smbios(MachineState *ms, FWCfgState *fw_cfg);
 void fw_cfg_build_feature_control(MachineState *ms, FWCfgState *fw_cfg);
 void fw_cfg_add_acpi_dsdt(Aml *scope, FWCfgState *fw_cfg);
+void fw_cfg_phys_bits(FWCfgState *fw_cfg);
 
 #endif
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index c95333514ed3..bedef1ee13c1 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -119,6 +119,7 @@ struct PCMachineClass {
     bool enforce_aligned_dimm;
     bool broken_reserved_end;
     bool enforce_amd_1tb_hole;
+    bool phys_bits_in_fw_cfg;
 
     /* generate legacy CPU hotplug AML */
     bool legacy_cpu_hotplug;
diff --git a/hw/i386/fw_cfg.c b/hw/i386/fw_cfg.c
index a283785a8de4..6a1f18925725 100644
--- a/hw/i386/fw_cfg.c
+++ b/hw/i386/fw_cfg.c
@@ -219,3 +219,15 @@ void fw_cfg_add_acpi_dsdt(Aml *scope, FWCfgState *fw_cfg)
     aml_append(dev, aml_name_decl("_CRS", crs));
     aml_append(scope, dev);
 }
+
+void fw_cfg_phys_bits(FWCfgState *fw_cfg)
+{
+    X86CPU *cpu = X86_CPU(first_cpu);
+    uint64_t phys_bits = cpu->phys_bits;
+
+    if (cpu->host_phys_bits) {
+        fw_cfg_add_file(fw_cfg, "etc/phys-bits",
+                        g_memdup2(&phys_bits, sizeof(phys_bits)),
+                        sizeof(phys_bits));
+    }
+}
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 566accf7e60a..17ecc7fe4331 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -744,6 +744,7 @@ void pc_machine_done(Notifier *notifier, void *data)
 {
     PCMachineState *pcms = container_of(notifier,
                                         PCMachineState, machine_done);
+    PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
     X86MachineState *x86ms = X86_MACHINE(pcms);
 
     cxl_hook_up_pxb_registers(pcms->bus, &pcms->cxl_devices_state,
@@ -764,6 +765,9 @@ void pc_machine_done(Notifier *notifier, void *data)
         fw_cfg_build_feature_control(MACHINE(pcms), x86ms->fw_cfg);
         /* update FW_CFG_NB_CPUS to account for -device added CPUs */
         fw_cfg_modify_i16(x86ms->fw_cfg, FW_CFG_NB_CPUS, x86ms->boot_cpus);
+        if (pcmc->phys_bits_in_fw_cfg) {
+            fw_cfg_phys_bits(x86ms->fw_cfg);
+        }
     }
 }
 
@@ -1907,6 +1911,7 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
     pcmc->kvmclock_enabled = true;
     pcmc->enforce_aligned_dimm = true;
     pcmc->enforce_amd_1tb_hole = true;
+    pcmc->phys_bits_in_fw_cfg = true;
     /* BIOS ACPI tables: 128K. Other BIOS datastructures: less than 4K reported
      * to be used at the moment, 32K should be enough for a while.  */
     pcmc->acpi_data_size = 0x20000 + 0x8000;
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 8043a250adf3..c6a4dbd5c0b0 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -447,9 +447,11 @@ DEFINE_I440FX_MACHINE(v7_2, "pc-i440fx-7.2", NULL,
 
 static void pc_i440fx_7_1_machine_options(MachineClass *m)
 {
+    PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
     pc_i440fx_7_2_machine_options(m);
     m->alias = NULL;
     m->is_default = false;
+    pcmc->phys_bits_in_fw_cfg = false;
     compat_props_add(m->compat_props, hw_compat_7_1, hw_compat_7_1_len);
     compat_props_add(m->compat_props, pc_compat_7_1, pc_compat_7_1_len);
 }
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 53eda50e818c..c2b56daa1550 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -384,8 +384,10 @@ DEFINE_Q35_MACHINE(v7_2, "pc-q35-7.2", NULL,
 
 static void pc_q35_7_1_machine_options(MachineClass *m)
 {
+    PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
     pc_q35_7_2_machine_options(m);
     m->alias = NULL;
+    pcmc->phys_bits_in_fw_cfg = false;
     compat_props_add(m->compat_props, hw_compat_7_1, hw_compat_7_1_len);
     compat_props_add(m->compat_props, pc_compat_7_1, pc_compat_7_1_len);
 }
-- 
2.37.3


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2022-09-22  9:56 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2022-09-22  8:43 [PATCH v3] x86: add etc/phys-bits fw_cfg file Gerd Hoffmann
2022-09-22  8:55 ` Michael S. Tsirkin
2022-09-22  9:37   ` Gerd Hoffmann
2022-09-22  9:53     ` Michael S. Tsirkin
2022-09-22  9:55 ` Michael S. Tsirkin

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