KVM now supports reporting supported Hyper-V features through CPUID
(KVM_GET_SUPPORTED_HV_CPUID ioctl). Going forward, this is going to be
the only way to announce new functionality and this has already happened
with Direct Mode stimers.
While we could just support KVM_GET_SUPPORTED_HV_CPUID for new features,
it seems to be beneficial to use it for all Hyper-V enlightenments when
possible. This way we can implement 'hv-all' pass-through mode giving the
guest all supported Hyper-V features even when QEMU knows nothing about
them.
Implementation-wise we create a new kvm_hyperv_properties structure
defining Hyper-V features, get_supported_hv_cpuid()/
get_supported_hv_cpuid_legacy() returning the supported CPUID set and
a bit over-engineered hv_cpuid_check_and_set() which we will also be
used to set cpu->hyperv_* properties for 'hv-all' mode.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20190517141924.19024-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
QEMU tracks whether a vcpu is halted using CPUState::halted. E.g.,
after initialization or reset, halted is 0 for the BSP (vcpu 0)
and 1 for the APs (vcpu 1, 2, ...). A halted vcpu should not be
handed to the hypervisor to run (e.g. hax_vcpu_run()).
Under HAXM, Android Emulator sometimes boots into a "vcpu shutdown
request" error while executing in SeaBIOS, with the HAXM driver
logging a guest triple fault in vcpu 1, 2, ... at RIP 0x3. That is
ultimately because the HAX accelerator asks HAXM to run those APs
when they are still in the halted state.
Normally, the vcpu thread for an AP will start by looping in
qemu_wait_io_event(), until the BSP kicks it via a pair of IPIs
(INIT followed by SIPI). But because the HAX accelerator does not
honor cpu->halted, it allows the AP vcpu thread to proceed to
hax_vcpu_run() as soon as it receives any kick, even if the kick
does not come from the BSP. It turns out that emulator has a
worker thread which periodically kicks every vcpu thread (possibly
to collect CPU usage data), and if one of these kicks comes before
those by the BSP, the AP will start execution from the wrong RIP,
resulting in the aforementioned SMP boot failure.
The solution is inspired by the KVM accelerator (credit to
Chuanxiao Dong <chuanxiao.dong@intel.com> for the pointer):
1. Get rid of questionable logic that unconditionally resets
cpu->halted before hax_vcpu_run(). Instead, only reset it at the
right moments (there are only a few "unhalt" events).
2. Add a check for cpu->halted before hax_vcpu_run().
Note that although the non-Unrestricted Guest (!ug_platform) code
path also forcibly resets cpu->halted, it is left untouched,
because only the UG code path supports SMP guests.
The patch is first merged to android emulator with Change-Id:
I9c5752cc737fd305d7eace1768ea12a07309d716
Cc: Yu Ning <yu.ning@intel.com>
Cc: Chuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: Colin Xu <colin.xu@intel.com>
Message-Id: <20190610021939.13669-1-colin.xu@intel.com>
Miscellaneous patches for 2019-06-11
# gpg: Signature made Wed 12 Jun 2019 12:20:41 BST
# gpg: using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg: issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653
* remotes/armbru/tags/pull-misc-2019-06-11-v3:
MAINTAINERS: Polish headline decorations
MAINTAINERS: Improve section headlines
MAINTAINERS: Remove duplicate entries of qemu-devel@nongnu.org
Clean up a header guard symbols (again)
Supply missing header guards
Clean up a few header guard symbols
scripts/clean-header-guards: Fix handling of trailing comments
Normalize position of header guard
Include qemu-common.h exactly where needed
Include qemu/module.h where needed, drop it from qemu-common.h
qemu-common: Move qemu_isalnum() etc. to qemu/ctype.h
qemu-common: Move tcg_enabled() etc. to sysemu/tcg.h
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This is the common header guard idiom:
/*
* File comment
*/
#ifndef GUARD_SYMBOL_H
#define GUARD_SYMBOL_H
... actual contents ...
#endif
A few of our headers have some #include before the guard.
target/tilegx/spr_def_64.h has #ifndef __DOXYGEN__ outside the guard.
A few more have the #define elsewhere.
Change them to match the common idiom. For spr_def_64.h, that means
dropping #ifndef __DOXYGEN__. While there, rename guard symbols to
make scripts/clean-header-guards.pl happy.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190604181618.19980-2-armbru@redhat.com>
[Rebased with conflicts resolved automatically]
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
Other accelerators have their own headers: sysemu/hax.h, sysemu/hvf.h,
sysemu/kvm.h, sysemu/whpx.h. Only tcg_enabled() & friends sit in
qemu-common.h. This necessitates inclusion of qemu-common.h into
headers, which is against the rules spelled out in qemu-common.h's
file comment.
Move tcg_enabled() & friends into their own header sysemu/tcg.h, and
adjust #include directives.
Cc: Richard Henderson <rth@twiddle.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-2-armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[Rebased with conflicts resolved automatically, except for
accel/tcg/tcg-all.c]
i386 (32 bit) emulation uses EFER in wrmsr and in MMU fault
processing.
But it does not included in VMState, because "efer" field is disabled with
This patch adds a section for 32-bit targets which saves EFER when
it's value is non-zero.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <155913371654.8429.1659082639780315242.stgit@pasha-Precision-3630-Tower>
Reviewed-by: Peter Xu <peterx@redhat.com>
[ehabkost: indentation fix]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Add a "unavailable-features" QOM property to X86CPU objects that
have the same semantics of "unavailable-features" on
query-cpu-definitions. The new property has the same goal of
"filtered-features", but is generic enough to let any kind of CPU
feature to be listed there without relying on low level details
like CPUID leaves or MSR numbers.
Message-Id: <20190422234742.15780-3-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Extract feature name listing code from
x86_cpu_class_check_missing_features(). It will be reused to
return information about CPU filtered features at runtime.
Message-Id: <20190422234742.15780-2-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This macro is now always empty, so remove it. This leaves the
entire contents of CPUArchState under the control of the guest
architecture.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Cleanup in the boilerplate that each target must define.
Replace x86_env_get_cpu with env_archcpu. The combination
CPU(x86_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
For all targets, into this new file move TARGET_LONG_BITS,
TARGET_PAGE_BITS, TARGET_PHYS_ADDR_SPACE_BITS,
TARGET_VIRT_ADDR_SPACE_BITS, and NB_MMU_MODES.
Include this new file from exec/cpu-defs.h.
This now removes the somewhat odd requirement that target/arch/cpu.h
defines TARGET_LONG_BITS before including exec/cpu-defs.h, so push the
bulk of the includes within target/arch/cpu.h to the top.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Introduce qemu_guest_getrandom.
Use qemu_guest_getrandom in aspeed, nrf51, bcm2835, exynos4210 rng devices.
Use qemu_guest_getrandom in target/ppc darn instruction.
Support ARMv8.5-RNG extension.
Support x86 RDRAND extension.
Acked-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Laurent Vivier <laurent@vivier.eu>
# gpg: Signature made Wed 22 May 2019 19:36:43 BST
# gpg: using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg: issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A 05C0 64DF 38E8 AF7E 215F
* remotes/rth/tags/pull-rng-20190522: (25 commits)
target/i386: Implement CPUID_EXT_RDRAND
target/ppc: Use qemu_guest_getrandom for DARN
target/ppc: Use gen_io_start/end around DARN
target/arm: Implement ARMv8.5-RNG
target/arm: Put all PAC keys into a structure
hw/misc/exynos4210_rng: Use qemu_guest_getrandom
hw/misc/bcm2835_rng: Use qemu_guest_getrandom_nofail
hw/misc/nrf51_rng: Use qemu_guest_getrandom_nofail
aspeed/scu: Use qemu_guest_getrandom_nofail
linux-user: Remove srand call
linux-user/aarch64: Use qemu_guest_getrandom for PAUTH keys
linux-user: Use qemu_guest_getrandom_nofail for AT_RANDOM
linux-user: Call qcrypto_init if not using -seed
linux-user: Initialize pseudo-random seeds for all guest cpus
cpus: Initialize pseudo-random seeds for all guest cpus
util: Add qemu_guest_getrandom and associated routines
ui/vnc: Use gcrypto_random_bytes for start_auth_vnc
ui/vnc: Split out authentication_failed
crypto: Change the qcrypto_random_bytes buffer type to void*
crypto: Use getrandom for qcrypto_random_bytes
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Microarchitectural Data Sampling is a hardware vulnerability which allows
unprivileged speculative access to data which is available in various CPU
internal buffers.
Some Intel processors use the ARCH_CAP_MDS_NO bit in the
IA32_ARCH_CAPABILITIES
MSR to report that they are not vulnerable, make it available to guests.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20190516185320.28340-1-pbonzini@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
md-clear is a new CPUID bit which is set when microcode provides the
mechanism to invoke a flush of various exploitable CPU buffers by invoking
the VERW instruction.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20190515141011.5315-2-berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Mostly bugfixes and cleanups, the most important being
"megasas: fix mapped frame size" from Peter Lieven.
In addition, -realtime is marked as deprecated.
# gpg: Signature made Fri 17 May 2019 14:25:11 BST
# gpg: using RSA key BFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1
# Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83
* remotes/bonzini/tags/for-upstream: (21 commits)
hw/net/ne2000: Extract the PCI device from the chipset common code
hw/char: Move multi-serial devices into separate file
ioapic: allow buggy guests mishandling level-triggered interrupts to make progress
build: don't build hardware objects with linux-user
build: chardev is only needed for softmmu targets
configure: qemu-ga is only needed with softmmu targets
build: replace GENERATED_FILES by generated-files-y
trace: only include trace-event-subdirs when they are needed
sun4m: obey -vga none
mips-fulong2e: obey -vga none
hw/i386/acpi: Assert a pointer is not null BEFORE using it
hw/i386/acpi: Add object_resolve_type_unambiguous to improve modularity
hw/acpi/piix4: Move TYPE_PIIX4_PM to a public header
memory: correct the comment to DIRTY_MEMORY_MIGRATION
vl: fix -sandbox parsing crash when seccomp support is disabled
hvf: Add missing break statement
megasas: fix mapped frame size
vl: Add missing descriptions to the VGA adapters list
Declare -realtime as deprecated
roms: assert if max rom size is less than the used size
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
In target/i386/hvf/hvf.c, a break statement was probably missing in
`hvf_vcpu_exec()`, in handling EXIT_REASON_HLT.
These lines seemed to be equivalent to `kvm_handle_halt()`.
Signed-off-by: Chen Zhang <tgfbeta@me.com>
Message-Id: <087F1D9C-109D-41D1-BE2C-CE5D840C981B@me.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add CPUClass::tlb_fill.
Improve tlb_vaddr_to_host for use by ARM SVE no-fault loads.
# gpg: Signature made Fri 10 May 2019 19:48:37 BST
# gpg: using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg: issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A 05C0 64DF 38E8 AF7E 215F
* remotes/rth/tags/pull-tcg-20190510: (27 commits)
tcg: Use tlb_fill probe from tlb_vaddr_to_host
tcg: Remove CPUClass::handle_mmu_fault
tcg: Use CPUClass::tlb_fill in cputlb.c
target/xtensa: Convert to CPUClass::tlb_fill
target/unicore32: Convert to CPUClass::tlb_fill
target/tricore: Convert to CPUClass::tlb_fill
target/tilegx: Convert to CPUClass::tlb_fill
target/sparc: Convert to CPUClass::tlb_fill
target/sh4: Convert to CPUClass::tlb_fill
target/s390x: Convert to CPUClass::tlb_fill
target/riscv: Convert to CPUClass::tlb_fill
target/ppc: Convert to CPUClass::tlb_fill
target/openrisc: Convert to CPUClass::tlb_fill
target/nios2: Convert to CPUClass::tlb_fill
target/moxie: Convert to CPUClass::tlb_fill
target/mips: Convert to CPUClass::tlb_fill
target/mips: Tidy control flow in mips_cpu_handle_mmu_fault
target/mips: Pass a valid error to raise_mmu_exception for user-only
target/microblaze: Convert to CPUClass::tlb_fill
target/m68k: Convert to CPUClass::tlb_fill
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We commonly define the header guard symbol without an explicit value.
Normalize the exceptions.
Done with scripts/clean-header-guards.pl.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190315145123.28030-8-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Leading underscores are ill-advised because such identifiers are
reserved. Trailing underscores are merely ugly. Strip both.
Our header guards commonly end in _H. Normalize the exceptions.
Done with scripts/clean-header-guards.pl.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190315145123.28030-7-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Changes to slirp/ dropped, as we're about to spin it off]
Header guard symbols should match their file name to make guard
collisions less likely.
Cleaned up with scripts/clean-header-guards.pl, followed by some
renaming of new guard symbols picked by the script to better ones.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190315145123.28030-6-armbru@redhat.com>
[Rebase to master: update include/hw/net/ne2000-isa.h]
We can now use the CPUClass hook instead of a named function.
Create a static tlb_fill function to avoid other changes within
cputlb.c. This also isolates the asserts within. Remove the
named tlb_fill function from all of the targets.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Add tcg_gen_extract2_*.
Deal with overflow of TranslationBlocks.
Respect access_type in io_readx.
# gpg: Signature made Fri 26 Apr 2019 18:17:01 BST
# gpg: using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg: issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A 05C0 64DF 38E8 AF7E 215F
* remotes/rth/tags/pull-tcg-20190426:
cputlb: Fix io_readx() to respect the access_type
tcg/arm: Restrict constant pool displacement to 12 bits
tcg/ppc: Allow the constant pool to overflow at 32k
tcg: Restart TB generation after out-of-line ldst overflow
tcg: Restart TB generation after constant pool overflow
tcg: Restart TB generation after relocation overflow
tcg: Restart after TB code generation overflow
tcg: Hoist max_insns computation to tb_gen_code
tcg/aarch64: Support INDEX_op_extract2_{i32,i64}
tcg/arm: Support INDEX_op_extract2_i32
tcg/i386: Support INDEX_op_extract2_{i32,i64}
tcg: Use extract2 in tcg_gen_deposit_{i32,i64}
tcg: Use deposit and extract2 in tcg_gen_shifti_i64
tcg: Add INDEX_op_extract2_{i32,i64}
tcg: Implement tcg_gen_extract2_{i32,i64}
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Add a new base CPU model called 'Dhyana' to model processors from Hygon
Dhyana(family 18h), which derived from AMD EPYC(family 17h).
The following features bits have been removed compare to AMD EPYC:
aes, pclmulqdq, sha_ni
The Hygon Dhyana support to KVM in Linux is already accepted upstream[1].
So add Hygon Dhyana support to Qemu is necessary to create Hygon's own
CPU model.
Reference:
[1] https://git.kernel.org/tip/fec98069fb72fb656304a3e52265e0c2fc9adf87
Signed-off-by: Pu Wen <puwen@hygon.cn>
Message-Id: <1555416373-28690-1-git-send-email-puwen@hygon.cn>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
In order to handle TB's that translate to too much code, we
need to place the control of the length of the translation
in the hands of the code gen master loop.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
CPUClass method dump_statistics() takes an fprintf()-like callback and
a FILE * to pass to it. Most callers pass fprintf() and stderr.
log_cpu_state() passes fprintf() and qemu_log_file.
hmp_info_registers() passes monitor_fprintf() and the current monitor
cast to FILE *. monitor_fprintf() casts it right back, and is
otherwise identical to monitor_printf().
The callback gets passed around a lot, which is tiresome. The
type-punning around monitor_fprintf() is ugly.
Drop the callback, and call qemu_fprintf() instead. Also gets rid of
the type-punning, since qemu_fprintf() takes NULL instead of the
current monitor cast to FILE *.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190417191805.28198-15-armbru@redhat.com>
x86_cpu_dump_local_apic_state() takes an fprintf()-like callback and a
FILE * to pass to it, and so do its helper functions.
Its only caller hmp_info_local_apic() passes monitor_fprintf() and the
current monitor cast to FILE *. monitor_fprintf() casts it right
back, and is otherwise identical to monitor_printf(). The
type-punning is ugly.
Drop the callback, and call qemu_printf() instead.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190417191805.28198-12-armbru@redhat.com>
The various TARGET_cpu_list() take an fprintf()-like callback and a
FILE * to pass to it. Their callers (vl.c's main() via list_cpus(),
bsd-user/main.c's main(), linux-user/main.c's main()) all pass
fprintf() and stdout. Thus, the flexibility provided by the (rather
tiresome) indirection isn't actually used.
Drop the callback, and call qemu_printf() instead.
Calling printf() would also work, but would make the code unsuitable
for monitor context without making it simpler.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190417191805.28198-10-armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Currently, the Cascadelake-Server, Icelake-Client, and
Icelake-Server are always generating the following warning:
qemu-system-x86_64: warning: \
host doesn't support requested feature: CPUID.07H:ECX [bit 4]
This happens because OSPKE was never returned by
GET_SUPPORTED_CPUID or x86_cpu_get_supported_feature_word().
OSPKE is a runtime flag automatically set by the KVM module or by
TCG code, was always cleared by x86_cpu_filter_features(), and
was not supposed to appear on the CPU model table.
Remove the OSPKE flag from the CPU model table entries, to avoid
the bogus warning and avoid returning invalid feature data on
query-cpu-* QMP commands. As OSPKE was always cleared by
x86_cpu_filter_features(), this won't have any guest-visible
impact.
Include a test case that should detect the problem if we introduce
a similar bug again.
Fixes: c7a88b52f6 ("i386: Add new model of Cascadelake-Server")
Fixes: 8a11c62da9 ("i386: Add new CPU model Icelake-{Server,Client}")
Cc: Tao Xu <tao3.xu@intel.com>
Cc: Robert Hoo <robert.hu@linux.intel.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20190319200515.14999-1-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Now that kvm_arch_get_supported_cpuid() will only return
arch_capabilities if QEMU is able to initialize the MSR properly,
we know that the feature is safely migratable.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20190125220606.4864-3-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
KVM has two bugs in the handling of MSR_IA32_ARCH_CAPABILITIES:
1) Linux commit commit 1eaafe91a0df ("kvm: x86: IA32_ARCH_CAPABILITIES
is always supported") makes GET_SUPPORTED_CPUID return
arch_capabilities even if running on SVM. This makes "-cpu
host,migratable=off" incorrectly expose arch_capabilities on CPUID on
AMD hosts (where the MSR is not emulated by KVM).
2) KVM_GET_MSR_INDEX_LIST does not return MSR_IA32_ARCH_CAPABILITIES if
the MSR is not supported by the host CPU. This makes QEMU not
initialize the MSR properly at kvm_put_msrs() on those hosts.
Work around both bugs on the QEMU side, by checking if the MSR
was returned by KVM_GET_MSR_INDEX_LIST before returning the
feature flag on kvm_arch_get_supported_cpuid().
This has the unfortunate side effect of making arch_capabilities
unavailable on hosts without hardware support for the MSR until bug #2
is fixed on KVM, but I can't see another way to work around bug #1
without that side effect.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20190125220606.4864-2-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
The CPUID code will call kvm_arch_get_supported_cpuid() and, even though
it is undef kvm_enabled() so it never runs for user-mode emulators,
sometimes clang will not optimize it out at -O0.
That could be considered a compiler bug, however at -O0 we give it
a pass and just add the stubs.
Reported-by: Kamil Rytarowski <n54@gmx.com>
Tested-by: Kamil Rytarowski <n54@gmx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
