Starting with Windows Server 2012 and Windows 8, if
CPUID.40000005.EAX contains a value of -1, Windows assumes specific
limit to the number of VPs. In this case, Windows Server 2012
guest VMs may use more than 64 VPs, up to the maximum supported
number of processors applicable to the specific Windows
version being used.
https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs
For compatibility, Let's introduce a new property for X86CPU,
named "x-hv-max-vps" as Eduardo's suggestion, and set it
to 0x40 before machine 2.10.
(The "x-" prefix indicates that the property is not supposed to
be a stable user interface.)
Backports relevant parts of commit 6c69dfb67e84747cf071958594d939e845dfcc0c from qemu
Currently when running KVM, we expose "KVMKVMKVM\0\0\0" in
the 0x40000000 CPUID leaf. Other hypervisors (VMWare,
HyperV, Xen, BHyve) all do the same thing, which leaves
TCG as the odd one out.
The CPUID signature is used by software to detect which
virtual environment they are running in and (potentially)
change behaviour in certain ways. For example, systemd
supports a ConditionVirtualization= setting in unit files.
The virt-what command can also report the virt type it is
running on
Currently both these apps have to resort to custom hacks
like looking for 'fw-cfg' entry in the /proc/device-tree
file to identify TCG.
This change thus proposes a signature "TCGTCGTCGTCG" to be
reported when running under TCG.
To hide this, the -cpu option tcg-cpuid=off can be used.
Backports commits 4ed3d478c63dc65a02eba774c35116618ea5ff10 and 1ce36bfe6424243082d3d7c2330e1a0a4ff72a43 from qemu
Move cpu_get_fp80()/cpu_set_fp80() from fpu_helper.c to
machine.c because fpu_helper.c will be disabled if tcg is
disabled in the build.
Backports commit db573d2cf7ae6b5a4fc324be6f55e078fc218464 from qemu.
In unicorn's case, they can be moved into unicorn.c
This speeds up SMM switches. Later on it may remove the need to take
the BQL, and it may also allow to reuse code between TCG and KVM.
Backports commit f8c45c6550b9ff1e1f0b92709ff3213a79870879 from qemu
The existing code for "host" and "max" CPU models overrides every
single feature in the CPU object at realize time, even the ones
that were explicitly enabled or disabled by the user using
"feat=on" or "feat=off", while features set using +feat/-feat are
kept.
This means "-cpu host,+invtsc" works as expected, while
"-cpu host,invtsc=on" doesn't.
This was a known bug, already documented in a comment inside
x86_cpu_expand_features(). What makes this bug worse now is that
libvirt 3.0.0 and newer now use "feat=on|off" instead of
+feat/-feat when it detects a QEMU version that supports it (see
libvirt commit d47db7b16dd5422c7e487c8c8ee5b181a2f9cd66).
Change the feature property getter/setter to set a
env->user_features field, to keep track of features that were
explicitly changed using QOM properties. Then make the
max_features code not override user features when handling "-cpu
host" and "-cpu max".
This will also allow us to remove the plus_features/minus_features
hack in the future, but I plan to do that after 2.9.0 is
released.
Backports commit d4a606b38b5d4b3689b86cc1575908e82179ecfb from qemu
Helper function for code that needs to check the host CPU
vendor/family/model/stepping values.
Backports commit 20271d484069f154fb262507e63adc3a37e885d2 from qemu
Paths through the softmmu code during code generation now need to be audited
to check for double locking of tb_lock. In particular, VMEXIT can take tb_lock
through cpu_vmexit -> cpu_x86_update_cr4 -> tlb_flush.
To avoid this, split VMEXIT delivery in two parts, similar to what is done with
exceptions. cpu_vmexit only records the VMEXIT exit code and information, and
cc->do_interrupt can then deliver it when it is safe to take the lock.
Backports commit 10cde894b63146139f981857e4eedf756fa53dcb from qemu
This suppresses the incorrect warning when forcing MTTCG for x86
guests on x86 hosts. A future patch will still warn when
TARGET_SUPPORT_MTTCG hasn't been defined for the guest (which is still
pending for x86).
Backports commit 72c1701f62e8d44eb24a0583a958edc280105455 from qemu
AVX512_VPOPCNTDQ: Vector POPCNT instructions for word and qwords.
variable precision.
Backports commit f77543772dcd38fa438470d9b80bafbd3a3ebbd7 from qemu
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.
Backports commit fcf5ef2ab52c621a4617ebbef36bf43b4003f4c0 from qemu
