On Thu, Oct 29, 2020 at 5:07 PM Dario Faggioli <dfaggioli@suse.com> wrote:
This patch maps /domain/cpu/maxphysaddr into -cpu parameters:

  - <maxphysaddr mode='passthrough'/> becomes host-phys-bits=on
  - <maxphysaddr mode='emualte' bits='42'/> becomes phys-bits=42

I can't thank you enough Dario for starting this,
I have waited for this quite a while and never found the time for it myself :-/

Looking at my todo notes I wondered if while touching it we should right away also
add host-phys-bits-limit in the same spot?
See https://git.qemu.org/?p=qemu.git;a=commit;h=258fe08bd341d
 
Passthrough mode can only be used if the chosen CPU model is
'host-passthrough'.

The feature is available since QEMU 2.7.0.

Signed-off-by: Dario Faggioli <dfaggioli@suse.com>
---
 src/qemu/qemu_capabilities.c                       |    2 +
 src/qemu/qemu_capabilities.h                       |    1
 src/qemu/qemu_command.c                            |   28 ++++++++++++
 src/qemu/qemu_domain.c                             |   46 ++++++++++++++++++++
 tests/qemuxml2argvdata/cpu-phys-bits-emulate.args  |   29 +++++++++++++
 tests/qemuxml2argvdata/cpu-phys-bits-emulate.xml   |   20 +++++++++
 tests/qemuxml2argvdata/cpu-phys-bits-emulate2.args |   30 +++++++++++++
 tests/qemuxml2argvdata/cpu-phys-bits-emulate2.xml  |   20 +++++++++
 tests/qemuxml2argvdata/cpu-phys-bits-emulate3.err  |    1
 tests/qemuxml2argvdata/cpu-phys-bits-emulate3.xml  |   20 +++++++++
 .../cpu-phys-bits-passthrough.args                 |   29 +++++++++++++
 .../qemuxml2argvdata/cpu-phys-bits-passthrough.xml |   20 +++++++++
 .../cpu-phys-bits-passthrough2.err                 |    1
 .../cpu-phys-bits-passthrough2.xml                 |   20 +++++++++
 .../cpu-phys-bits-passthrough3.err                 |    1
 .../cpu-phys-bits-passthrough3.xml                 |   20 +++++++++
 tests/qemuxml2argvtest.c                           |    7 +++
 17 files changed, 295 insertions(+)
 create mode 100644 tests/qemuxml2argvdata/cpu-phys-bits-emulate.args
 create mode 100644 tests/qemuxml2argvdata/cpu-phys-bits-emulate.xml
 create mode 100644 tests/qemuxml2argvdata/cpu-phys-bits-emulate2.args
 create mode 100644 tests/qemuxml2argvdata/cpu-phys-bits-emulate2.xml
 create mode 100644 tests/qemuxml2argvdata/cpu-phys-bits-emulate3.err
 create mode 100644 tests/qemuxml2argvdata/cpu-phys-bits-emulate3.xml
 create mode 100644 tests/qemuxml2argvdata/cpu-phys-bits-passthrough.args
 create mode 100644 tests/qemuxml2argvdata/cpu-phys-bits-passthrough.xml
 create mode 100644 tests/qemuxml2argvdata/cpu-phys-bits-passthrough2.err
 create mode 100644 tests/qemuxml2argvdata/cpu-phys-bits-passthrough2.xml
 create mode 100644 tests/qemuxml2argvdata/cpu-phys-bits-passthrough3.err
 create mode 100644 tests/qemuxml2argvdata/cpu-phys-bits-passthrough3.xml

diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index a67fb785b5..70adb423f1 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -603,6 +603,7 @@ VIR_ENUM_IMPL(virQEMUCaps,
               "virtio-balloon.free-page-reporting",
               "block-export-add",
               "netdev.vhost-vdpa",
+              "host-phys-bits",
     );


@@ -1679,6 +1680,7 @@ static struct virQEMUCapsStringFlags virQEMUCapsObjectPropsMaxCPU[] = {
     { "unavailable-features", QEMU_CAPS_CPU_UNAVAILABLE_FEATURES },
     { "kvm-no-adjvtime", QEMU_CAPS_CPU_KVM_NO_ADJVTIME },
     { "migratable", QEMU_CAPS_CPU_MIGRATABLE },
+    { "host-phys-bits", QEMU_CAPS_CPU_PHYS_BITS },
 };

 static virQEMUCapsObjectTypeProps virQEMUCapsObjectProps[] = {
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 047ba8a0ee..0fe97d2fd1 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -583,6 +583,7 @@ typedef enum { /* virQEMUCapsFlags grouping marker for syntax-check */
     QEMU_CAPS_VIRTIO_BALLOON_FREE_PAGE_REPORTING, /*virtio balloon free-page-reporting */
     QEMU_CAPS_BLOCK_EXPORT_ADD, /* 'block-export-add' command is supported */
     QEMU_CAPS_NETDEV_VHOST_VDPA, /* -netdev vhost-vdpa*/
+    QEMU_CAPS_CPU_PHYS_BITS, /* -cpu phys-bits=42 or host-phys-bits=on */

     QEMU_CAPS_LAST /* this must always be the last item */
 } virQEMUCapsFlags;
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 7847706594..d58f80547e 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -6507,6 +6507,34 @@ qemuBuildCpuCommandLine(virCommandPtr cmd,
             virBufferAddLit(&buf, ",l3-cache=off");
     }

+    if (def->cpu && def->cpu->addr) {
+        virCPUMaxPhysAddrDefPtr addr = def->cpu->addr;
+
+        switch (addr->mode) {
+        case VIR_CPU_MAX_PHYS_ADDR_MODE_PASSTHROUGH:
+            if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_CPU_PHYS_BITS))
+               virBufferAddLit(&buf, ",host-phys-bits=on");
+            else
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("Setting host physical address bits is "
+                                 "not supported by this QEMU"));
+            break;
+
+        case VIR_CPU_MAX_PHYS_ADDR_MODE_EMULATE:
+            if (addr->bits != -1 &&
+                virQEMUCapsGet(qemuCaps, QEMU_CAPS_CPU_PHYS_BITS))
+                virBufferAsprintf(&buf, ",phys-bits=%d", addr->bits);
+            else
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("Physical address bits unspecified or "
+                                 "setting it not supported by this QEMU"));
+            break;
+
+        case VIR_CPU_MAX_PHYS_ADDR_MODE_LAST:
+            break;
+        }
+    }
+
     cpu = virBufferContentAndReset(&cpu_buf);
     cpu_flags = virBufferContentAndReset(&buf);

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index d7dbca487a..e9f20d82a1 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -4051,6 +4051,52 @@ qemuDomainDefCPUPostParse(virDomainDefPtr def,
         }
     }

+    if (def->cpu->addr) {
+        virCPUMaxPhysAddrDefPtr addr = def->cpu->addr;
+
+        if (!ARCH_IS_X86(def->os.arch)) {
+            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                           _("CPU maximum physical address bits specification "
+                             "is not supported  for '%s' architecture"),
+                           virArchToString(def->os.arch));
+            return -1;
+        }
+
+        switch (addr->mode) {
+        case VIR_CPU_MAX_PHYS_ADDR_MODE_PASSTHROUGH:
+            if (def->cpu->mode != VIR_CPU_MODE_HOST_PASSTHROUGH) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                               _("CPU maximum physical address bits mode '%s' "
+                                 "can only be used with '%s' CPUs"),
+                               virCPUMaxPhysAddrModeTypeToString(addr->mode),
+                               virCPUModeTypeToString(VIR_CPU_MODE_HOST_PASSTHROUGH));
+                return -1;
+            }
+            if (addr->bits != -1) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                               _("CPU maximum physical address bits number "
+                                 "specification cannot be used with "
+                                 "mode='%s'"),
+                               virCPUMaxPhysAddrModeTypeToString(VIR_CPU_MAX_PHYS_ADDR_MODE_PASSTHROUGH));
+                return -1;
+            }
+            break;
+
+        case VIR_CPU_MAX_PHYS_ADDR_MODE_EMULATE:
+            if (addr->bits == -1) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                               _("if using CPU maximum physical address "
+                                 "mode='%s', bits= must be specified too"),
+                               virCPUMaxPhysAddrModeTypeToString(VIR_CPU_MAX_PHYS_ADDR_MODE_EMULATE));
+                return -1;
+            }
+            break;
+
+        case VIR_CPU_MAX_PHYS_ADDR_MODE_LAST:
+            break;
+        }
+    }
+
     for (i = 0; i < def->cpu->nfeatures; i++) {
         virCPUFeatureDefPtr feature = &def->cpu->features[i];

diff --git a/tests/qemuxml2argvdata/cpu-phys-bits-emulate.args b/tests/qemuxml2argvdata/cpu-phys-bits-emulate.args
new file mode 100644
index 0000000000..5627b41b25
--- /dev/null
+++ b/tests/qemuxml2argvdata/cpu-phys-bits-emulate.args
@@ -0,0 +1,29 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-foo \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-foo/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-foo/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-foo/.config \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-x86_64 \
+-name foo \
+-S \
+-machine pc,accel=kvm,usb=off,dump-guest-core=off \
+-cpu host,phys-bits=42 \
+-m 214 \
+-realtime mlock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,path=/tmp/lib/domain--1-foo/monitor.sock,server,\
+nowait \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-usb \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3
diff --git a/tests/qemuxml2argvdata/cpu-phys-bits-emulate.xml b/tests/qemuxml2argvdata/cpu-phys-bits-emulate.xml
new file mode 100644
index 0000000000..f8bd63bc68
--- /dev/null
+++ b/tests/qemuxml2argvdata/cpu-phys-bits-emulate.xml
@@ -0,0 +1,20 @@
+<domain type='kvm'>
+  <name>foo</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='host-passthrough'>
+    <maxphysaddr mode='emulate' bits='42'/>
+  </cpu>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvdata/cpu-phys-bits-emulate2.args b/tests/qemuxml2argvdata/cpu-phys-bits-emulate2.args
new file mode 100644
index 0000000000..f105f96f02
--- /dev/null
+++ b/tests/qemuxml2argvdata/cpu-phys-bits-emulate2.args
@@ -0,0 +1,30 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-foo \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-foo/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-foo/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-foo/.config \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-x86_64 \
+-name foo \
+-S \
+-machine pc,accel=kvm,usb=off,dump-guest-core=off \
+-cpu core2duo,+ds,+acpi,+ss,+ht,+tm,+pbe,+ds_cpl,+vmx,+est,+tm2,+cx16,+xtpr,\
++lahf_lm,phys-bits=42 \
+-m 214 \
+-realtime mlock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,path=/tmp/lib/domain--1-foo/monitor.sock,server,\
+nowait \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-usb \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3
diff --git a/tests/qemuxml2argvdata/cpu-phys-bits-emulate2.xml b/tests/qemuxml2argvdata/cpu-phys-bits-emulate2.xml
new file mode 100644
index 0000000000..188b3066ed
--- /dev/null
+++ b/tests/qemuxml2argvdata/cpu-phys-bits-emulate2.xml
@@ -0,0 +1,20 @@
+<domain type='kvm'>
+  <name>foo</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='host-model'>
+    <maxphysaddr bits='42' mode='emulate'/>
+  </cpu>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvdata/cpu-phys-bits-emulate3.err b/tests/qemuxml2argvdata/cpu-phys-bits-emulate3.err
new file mode 100644
index 0000000000..5e21998259
--- /dev/null
+++ b/tests/qemuxml2argvdata/cpu-phys-bits-emulate3.err
@@ -0,0 +1 @@
+unsupported configuration: if using CPU maximum physical address mode='emulate', bits= must be specified too
diff --git a/tests/qemuxml2argvdata/cpu-phys-bits-emulate3.xml b/tests/qemuxml2argvdata/cpu-phys-bits-emulate3.xml
new file mode 100644
index 0000000000..30a14894dd
--- /dev/null
+++ b/tests/qemuxml2argvdata/cpu-phys-bits-emulate3.xml
@@ -0,0 +1,20 @@
+<domain type='kvm'>
+  <name>foo</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='host-passthrough'>
+    <maxphysaddr mode='emulate'/>
+  </cpu>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvdata/cpu-phys-bits-passthrough.args b/tests/qemuxml2argvdata/cpu-phys-bits-passthrough.args
new file mode 100644
index 0000000000..a4f3f55bb9
--- /dev/null
+++ b/tests/qemuxml2argvdata/cpu-phys-bits-passthrough.args
@@ -0,0 +1,29 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/tmp/lib/domain--1-foo \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/tmp/lib/domain--1-foo/.local/share \
+XDG_CACHE_HOME=/tmp/lib/domain--1-foo/.cache \
+XDG_CONFIG_HOME=/tmp/lib/domain--1-foo/.config \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu-system-x86_64 \
+-name foo \
+-S \
+-machine pc,accel=kvm,usb=off,dump-guest-core=off \
+-cpu host,host-phys-bits=on \
+-m 214 \
+-realtime mlock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,path=/tmp/lib/domain--1-foo/monitor.sock,server,\
+nowait \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-no-acpi \
+-usb \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3
diff --git a/tests/qemuxml2argvdata/cpu-phys-bits-passthrough.xml b/tests/qemuxml2argvdata/cpu-phys-bits-passthrough.xml
new file mode 100644
index 0000000000..db570beb8d
--- /dev/null
+++ b/tests/qemuxml2argvdata/cpu-phys-bits-passthrough.xml
@@ -0,0 +1,20 @@
+<domain type='kvm'>
+  <name>foo</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='host-passthrough'>
+    <maxphysaddr mode='passthrough'/>
+  </cpu>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvdata/cpu-phys-bits-passthrough2.err b/tests/qemuxml2argvdata/cpu-phys-bits-passthrough2.err
new file mode 100644
index 0000000000..22009cc6e6
--- /dev/null
+++ b/tests/qemuxml2argvdata/cpu-phys-bits-passthrough2.err
@@ -0,0 +1 @@
+unsupported configuration: CPU maximum physical address bits mode 'passthrough' can only be used with 'host-passthrough' CPUs
diff --git a/tests/qemuxml2argvdata/cpu-phys-bits-passthrough2.xml b/tests/qemuxml2argvdata/cpu-phys-bits-passthrough2.xml
new file mode 100644
index 0000000000..511bbf9949
--- /dev/null
+++ b/tests/qemuxml2argvdata/cpu-phys-bits-passthrough2.xml
@@ -0,0 +1,20 @@
+<domain type='kvm'>
+  <name>foo</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='host-model'>
+    <maxphysaddr mode='passthrough'/>
+  </cpu>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvdata/cpu-phys-bits-passthrough3.err b/tests/qemuxml2argvdata/cpu-phys-bits-passthrough3.err
new file mode 100644
index 0000000000..28f2e43432
--- /dev/null
+++ b/tests/qemuxml2argvdata/cpu-phys-bits-passthrough3.err
@@ -0,0 +1 @@
+unsupported configuration: CPU maximum physical address bits number specification cannot be used with mode='passthrough'
diff --git a/tests/qemuxml2argvdata/cpu-phys-bits-passthrough3.xml b/tests/qemuxml2argvdata/cpu-phys-bits-passthrough3.xml
new file mode 100644
index 0000000000..a94e567dcb
--- /dev/null
+++ b/tests/qemuxml2argvdata/cpu-phys-bits-passthrough3.xml
@@ -0,0 +1,20 @@
+<domain type='kvm'>
+  <name>foo</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='host-passthrough'>
+    <maxphysaddr mode='passthrough' bits='42'/>
+  </cpu>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index c5a0095e0d..fd17fea744 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -3409,6 +3409,13 @@ mymain(void)

     DO_TEST_CAPS_LATEST("virtio-9p-multidevs");

+    DO_TEST("cpu-phys-bits-passthrough", QEMU_CAPS_KVM, QEMU_CAPS_CPU_PHYS_BITS);
+    DO_TEST("cpu-phys-bits-emulate", QEMU_CAPS_KVM, QEMU_CAPS_CPU_PHYS_BITS);
+    DO_TEST("cpu-phys-bits-emulate2", QEMU_CAPS_KVM, QEMU_CAPS_CPU_PHYS_BITS);
+    DO_TEST_PARSE_ERROR("cpu-phys-bits-emulate3", QEMU_CAPS_KVM);
+    DO_TEST_PARSE_ERROR("cpu-phys-bits-passthrough2", QEMU_CAPS_KVM);
+    DO_TEST_PARSE_ERROR("cpu-phys-bits-passthrough3", QEMU_CAPS_KVM);
+
     if (getenv("LIBVIRT_SKIP_CLEANUP") == NULL)
         virFileDeleteTree(fakerootdir);





--
Christian Ehrhardt
Staff Engineer, Ubuntu Server
Canonical Ltd