QEMU populates the apic_state attribute of x86 CPUs if supported by real
hardware or if SMP is active. When handling interrupts, it just checks whether
apic_state is populated to route the interrupt to the PIC or to the APIC.
However, chapter 10.4.3 of [1] requires that:
When IA32_APIC_BASE[11] is 0, the processor is functionally equivalent to an
IA-32 processor without an on-chip APIC.
This means that when apic_state is populated, QEMU needs to check for the
MSR_IA32_APICBASE_ENABLE flag in addition. Implement this which fixes some
real-world BIOSes.
[1] Intel 64 and IA-32 Architectures Software Developer's Manual, Vol. 3A:
System Programming Guide, Part 1
Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Message-Id: <20240106132546.21248-3-shentey@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The if statement currently uses double negation when executing the else branch.
So swap the branches and simplify the condition to make the code more
comprehensible.
Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Message-Id: <20240106132546.21248-2-shentey@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit extends the APIC ID to 32-bit long and remove the 255 max APIC
ID limit in userspace APIC. The array that manages local APICs is now
dynamically allocated based on the max APIC ID of created x86 machine.
Also, new x2APIC IPI destination determination scheme, self IPI and x2APIC
mode register access are supported.
Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
Message-Id: <20240111154404.5333-3-minhquangbui99@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
`kvm_enabled()` is compiled down to `0` and short-circuit logic is
used to remove references to undefined symbols at the compile stage.
Some build configurations with some compilers don't attempt to
simplify this logic down in some cases (the pattern appears to be
that the literal false must be the first term) and this was causing
some builds to emit references to undefined symbols.
An example of such a configuration is clang 16.0.6 with the following
configure: ./configure --enable-debug --without-default-features
--target-list=x86_64-softmmu --enable-tcg-interpreter
Signed-off-by: Daniel Hoffman <dhoff749@gmail.com>
Message-Id: <20231119203116.3027230-1-dhoff749@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This reverts commit 67f7e426e5.
Additionally to the automatic revert, I went over the code
and dropped all mentions of legacy_no_rng_seed manually,
effectively reverting a combination of 2 additional commits:
commit ffe2d2382e
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Wed Sep 21 11:31:34 2022 +0200
x86: re-enable rng seeding via SetupData
commit 3824e25db1
Author: Gerd Hoffmann <kraxel@redhat.com>
Date: Wed Aug 17 10:39:40 2022 +0200
x86: disable rng seeding via setup_data
Fixes: 67f7e426e5 ("hw/i386: pass RNG seed via setup_data entry")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Dov Murik <dovmurik@linux.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
rtc_get_memory() and rtc_set_memory() helpers only work with
TYPE_MC146818_RTC devices. 'memory' in their name refer to
the CMOS region. Rename them as mc146818rtc_get_cmos_data()
and mc146818rtc_set_cmos_data() to be explicit about what
they are doing.
Mechanical change doing:
$ sed -i -e 's/rtc_set_memory/mc146818rtc_set_cmos_data/g' \
$(git grep -wl rtc_set_memory)
$ sed -i -e 's/rtc_get_memory/mc146818rtc_get_cmos_data/g' \
$(git grep -wl rtc_get_memory)
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230210233116.80311-4-philmd@linaro.org>
rtc_get_memory() and rtc_set_memory() methods can not take any
TYPE_ISA_DEVICE object. They expect a TYPE_MC146818_RTC one.
Simplify the API by passing a MC146818RtcState.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230210233116.80311-3-philmd@linaro.org>
This function is not used anywhere outside this file, so
we can delete the prototype from include/hw/i386/x86.h and
make the function "static void".
This fixes when building with -Wall and using Clang
("Apple clang version 14.0.0 (clang-1400.0.29.202)"):
../hw/i386/x86.c:70:24: error: static function 'MACHINE' is used in an inline function with external linkage [-Werror,-Wstatic-in-inline]
MachineState *ms = MACHINE(x86ms);
^
include/hw/i386/x86.h:101:1: note: use 'static' to give inline function 'init_topo_info' internal linkage
void init_topo_info(X86CPUTopoInfo *topo_info, const X86MachineState *x86ms);
^
static
include/hw/boards.h:24:49: note: 'MACHINE' declared here
OBJECT_DECLARE_TYPE(MachineState, MachineClass, MACHINE)
^
Reported-by: Stefan Weil <sw@weilnetz.de>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221216220158.6317-6-philmd@linaro.org>
The setup_data links are appended to the compressed kernel image. Since
the kernel image is typically loaded at 0x100000, setup_data lives at
`0x100000 + compressed_size`, which does not get relocated during the
kernel's boot process.
The kernel typically decompresses the image starting at address
0x1000000 (note: there's one more zero there than the compressed image
above). This usually is fine for most kernels.
However, if the compressed image is actually quite large, then
setup_data will live at a `0x100000 + compressed_size` that extends into
the decompressed zone at 0x1000000. In other words, if compressed_size
is larger than `0x1000000 - 0x100000`, then the decompression step will
clobber setup_data, resulting in crashes.
Visually, what happens now is that QEMU appends setup_data to the kernel
image:
kernel image setup_data
|--------------------------||----------------|
0x100000 0x100000+l1 0x100000+l1+l2
The problem is that this decompresses to 0x1000000 (one more zero). So
if l1 is > (0x1000000-0x100000), then this winds up looking like:
kernel image setup_data
|--------------------------||----------------|
0x100000 0x100000+l1 0x100000+l1+l2
d e c o m p r e s s e d k e r n e l
|-------------------------------------------------------------|
0x1000000 0x1000000+l3
The decompressed kernel seemingly overwriting the compressed kernel
image isn't a problem, because that gets relocated to a higher address
early on in the boot process, at the end of startup_64. setup_data,
however, stays in the same place, since those links are self referential
and nothing fixes them up. So the decompressed kernel clobbers it.
Fix this by appending setup_data to the cmdline blob rather than the
kernel image blob, which remains at a lower address that won't get
clobbered.
This could have been done by overwriting the initrd blob instead, but
that poses big difficulties, such as no longer being able to use memory
mapped files for initrd, hurting performance, and, more importantly, the
initrd address calculation is hard coded in qboot, and it always grows
down rather than up, which means lots of brittle semantics would have to
be changed around, incurring more complexity. In contrast, using cmdline
is simple and doesn't interfere with anything.
The microvm machine has a gross hack where it fiddles with fw_cfg data
after the fact. So this hack is updated to account for this appending,
by reserving some bytes.
Fixup-by: Michael S. Tsirkin <mst@redhat.com>
Cc: x86@kernel.org
Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Message-Id: <20221230220725.618763-1-Jason@zx2c4.com>
Message-ID: <20230128061015-mutt-send-email-mst@kernel.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Eric Biggers <ebiggers@google.com>
Tested-by: Mathias Krause <minipli@grsecurity.net>
Specify maximum possible APIC ID assigned for current VM session to KVM
prior to the creation of vCPUs. By this setting, KVM can set up VM-scoped
data structure indexed by the APIC ID, e.g. Posted-Interrupt Descriptor
pointer table to support Intel IPI virtualization, with the most optimal
memory footprint.
It can be achieved by calling KVM_ENABLE_CAP for KVM_CAP_MAX_VCPU_ID
capability once KVM has enabled it. Ignoring the return error if KVM
doesn't support this capability yet.
Signed-off-by: Zeng Guang <guang.zeng@intel.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20220825025246.26618-1-guang.zeng@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We don't want it to be possible to re-read the RNG seed after ingesting
it, because this ruins forward secrecy. Currently, however, the setup
data section can just be re-read. Since the kernel is always read after
the setup data, use the selection of the kernel as a trigger to
re-initialize the RNG seed, just like we do on reboot, to preserve
forward secrecy.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Message-Id: <20220922152847.3670513-1-Jason@zx2c4.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Since this is read from fw_cfg on each boot, the kernel zeroing it out
alone is insufficient to prevent it from being used twice. And indeed on
reboot we always want a new seed, not the old one. So re-fill it in this
circumstance.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Message-Id: <20220921093134.2936487-3-Jason@zx2c4.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If setup_data is being read into a specific memory location, then
generally the setup_data address parameter is read first, so that the
caller knows where to read it into. In that case, we should return
setup_data containing the absolute addresses that are hard coded and
determined a priori. This is the case when kernels are loaded by BIOS,
for example. In contrast, when setup_data is read as a file, then we
shouldn't modify setup_data, since the absolute address will be wrong by
definition. This is the case when OVMF loads the image.
This allows setup_data to be used like normal, without crashing when EFI
tries to use it.
(As a small development note, strangely, fw_cfg_add_file_callback() was
exported but fw_cfg_add_bytes_callback() wasn't, so this makes that
consistent.)
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Laurent Vivier <laurent@vivier.eu>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Message-Id: <20220921093134.2936487-1-Jason@zx2c4.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rather than hardcoding the 4G boundary everywhere, introduce a
X86MachineState field @above_4g_mem_start and use it
accordingly.
This is in preparation for relocating ram-above-4g to be
dynamically start at 1T on AMD platforms.
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20220719170014.27028-2-joao.m.martins@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Legacy PIC (8259) cannot be supported for TDX guests since TDX module
doesn't allow directly interrupt injection. Using posted interrupts
for the PIC is not a viable option as the guest BIOS/kernel will not
do EOI for PIC IRQs, i.e. will leave the vIRR bit set.
Make PIC the property of common x86 machine type. Hence all x86
machines, including microvm, can disable it.
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Message-Id: <20220310122811.807794-3-xiaoyao.li@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The check on x86ms->apic_id_limit in pc_machine_done() had two problems.
Firstly, we need KVM to support the X2APIC API in order to allow IRQ
delivery to APICs >= 255. So we need to call/check kvm_enable_x2apic(),
which was done elsewhere in *some* cases but not all.
Secondly, microvm needs the same check. So move it from pc_machine_done()
to x86_cpus_init() where it will work for both.
The check in kvm_cpu_instance_init() is now redundant and can be dropped.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20220314142544.150555-1-dwmw2@infradead.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
commit
f862ddbb1a (hw/i386: Remove the deprecated pc-1.x machine types)
removed the last user of broken APIC ID compat knob,
but compat_apic_id_mode itself was forgotten.
Clean it up and simplify x86_cpu_apic_id_from_index()
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20220228131634.3389805-1-imammedo@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
As long as fw_cfg supports DMA, the new ROM can be used also on older
machine types because it has the same size as the existing one.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This removes a parameter from x86_load_linux, and will avoid code
duplication between the linux and multiboot cases once multiboot
starts to support DMA.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
SEV is a x86 specific feature, and the "sev_i386.h" header
is already in target/i386/. Rename it as "sev.h" to simplify.
Patch created mechanically using:
$ git mv target/i386/sev_i386.h target/i386/sev.h
$ sed -i s/sev_i386.h/sev.h/ $(git grep -l sev_i386.h)
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20211007161716.453984-15-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Because SGX EPC is enumerated through CPUID, EPC "devices" need to be
realized prior to realizing the vCPUs themselves, i.e. long before
generic devices are parsed and realized. From a virtualization
perspective, the CPUID aspect also means that EPC sections cannot be
hotplugged without paravirtualizing the guest kernel (hardware does
not support hotplugging as EPC sections must be locked down during
pre-boot to provide EPC's security properties).
So even though EPC sections could be realized through the generic
-devices command, they need to be created much earlier for them to
actually be usable by the guest. Place all EPC sections in a
contiguous block, somewhat arbitrarily starting after RAM above 4g.
Ensuring EPC is in a contiguous region simplifies calculations, e.g.
device memory base, PCI hole, etc..., allows dynamic calculation of the
total EPC size, e.g. exposing EPC to guests does not require -maxmem,
and last but not least allows all of EPC to be enumerated in a single
ACPI entry, which is expected by some kernels, e.g. Windows 7 and 8.
The new compound properties command for sgx like below:
......
-object memory-backend-epc,id=mem1,size=28M,prealloc=on \
-object memory-backend-epc,id=mem2,size=10M \
-M sgx-epc.0.memdev=mem1,sgx-epc.1.memdev=mem2
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20210719112136.57018-6-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In order to make SMP configuration a Machine property, we need a getter as
well as a setter. To simplify the implementation put everything that the
getter needs in the CpuTopology struct.
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210617155308.928754-7-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
A bus lock is acquired through either split locked access to writeback
(WB) memory or any locked access to non-WB memory. It is typically >1000
cycles slower than an atomic operation within a cache and can also
disrupts performance on other cores.
Virtual Machines can exploit bus locks to degrade the performance of
system. To address this kind of performance DOS attack coming from the
VMs, bus lock VM exit is introduced in KVM and it can report the bus
locks detected in guest. If enabled in KVM, it would exit to the
userspace to let the user enforce throttling policies once bus locks
acquired in VMs.
The availability of bus lock VM exit can be detected through the
KVM_CAP_X86_BUS_LOCK_EXIT. The returned bitmap contains the potential
policies supported by KVM. The field KVM_BUS_LOCK_DETECTION_EXIT in
bitmap is the only supported strategy at present. It indicates that KVM
will exit to userspace to handle the bus locks.
This patch adds a ratelimit on the bus locks acquired in guest as a
mitigation policy.
Introduce a new field "bus_lock_ratelimit" to record the limited speed
of bus locks in the target VM. The user can specify it through the
"bus-lock-ratelimit" as a machine property. In current implementation,
the default value of the speed is 0 per second, which means no
restrictions on the bus locks.
As for ratelimit on detected bus locks, simply set the ratelimit
interval to 1s and restrict the quota of bus lock occurence to the value
of "bus_lock_ratelimit". A potential alternative is to introduce the
time slice as a property which can help the user achieve more precise
control.
The detail of bus lock VM exit can be found in spec:
https://software.intel.com/content/www/us/en/develop/download/intel-architecture-instruction-set-extensions-programming-reference.html
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Message-Id: <20210521043820.29678-1-chenyi.qiang@intel.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
The code that sets/gets oem fields is duplicated in both PC and MICROVM
variants. This commit moves it to X86MachineState so that all x86
variants can use it and duplication is removed.
Signed-off-by: Marian Postevca <posteuca@mutex.one>
Message-Id: <20210221001737.24499-2-posteuca@mutex.one>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
