On ppc64, the PowerVM hypervisor runs with limited memory and a VCPU
creation during hotplug may fail during kvm_ioctl for KVM_CREATE_VCPU,
leading to termination of guest since errp is set to &error_fatal while
calling kvm_init_vcpu. This unexpected behaviour can be avoided by
pre-creating and parking vcpu on success or return error otherwise.
This enables graceful error delivery for any vcpu hotplug failures while
the guest can keep running.
Also introducing KVM AccelCPUClass to init cpu_target_realize for kvm.
Tested OK by repeatedly doing a hotplug/unplug of vcpus as below:
#virsh setvcpus hotplug 40
#virsh setvcpus hotplug 70
error: internal error: unable to execute QEMU command 'device_add':
kvmppc_cpu_realize: vcpu hotplug failed with -12
Signed-off by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Reported-by: Anushree Mathur <anushree.mathur@linux.vnet.ibm.com>
Suggested-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Suggested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Tested-by: Anushree Mathur <anushree.mathur@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
This is an experiment to further reduce the amount we throw into the
exec headers. It might not be as useful as I initially thought because
just under half of the users also need gdbserver_start().
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240620152220.2192768-3-alex.bennee@linaro.org>
PPC_VIRTUAL_HYPERVISOR_GET_CLASS is used in critical operations like
interrupts and TLB misses and is quite costly. Running the
kvm-unit-tests sieve program with radix MMU enabled thrashes the TCG
TLB and spends a lot of time in TLB and page table walking code. The
test takes 67 seconds to complete with a lot of time being spent in
code related to finding the vhyp class:
12.01% [.] g_str_hash
8.94% [.] g_hash_table_lookup
8.06% [.] object_class_dynamic_cast
6.21% [.] address_space_ldq
4.94% [.] __strcmp_avx2
4.28% [.] tlb_set_page_full
4.08% [.] address_space_translate_internal
3.17% [.] object_class_dynamic_cast_assert
2.84% [.] ppc_radix64_xlate
Keep a pointer to the class and avoid this lookup. This reduces the
execution time to 40 seconds.
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
target/ppc/kvm.c calls out to code in hw/ppc/spapr*.c; that code is
not present and fails to link if CONFIG_PSERIES is not enabled.
Adjust kvm.c to depend on CONFIG_PSERIES instead of TARGET_PPC64,
and compile out anything that requires cap_papr, because only
the pseries machine will call kvmppc_set_papr().
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Board reset requires writing a fresh CPU state. As far as KVM is
concerned, the only thing that blocks reset is that CPU state is
encrypted; therefore, kvm_cpus_are_resettable() can simply check
if that is the case.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The POWER9 DD1 and POWER10 DD1 chips are not public and are no longer of
any use in QEMU. Remove them.
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Mechanical patch produced running the command documented
in scripts/coccinelle/cpu_env.cocci_template header.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240129164514.73104-22-philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
When a variable is initialized to &struct->field, use it
in place. Rationale: while this makes the code more concise,
this also helps static analyzers.
Mechanical change using the following Coccinelle spatch script:
@@
type S, F;
identifier s, m, v;
@@
S *s;
...
F *v = &s->m;
<+...
- &s->m
+ v
...+>
Inspired-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240129164514.73104-2-philmd@linaro.org>
Acked-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
[thuth: Dropped hunks that need a rebase, and fixed sizeof() in pmu_realize()]
Signed-off-by: Thomas Huth <thuth@redhat.com>
HPTES_PER_GROUP is 8 and HASH_PTE_SIZE_64 is 16, so we don't waste
too many bytes by always allocating the maximum amount of bytes on
the stack here to get rid of the variable length array.
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Message-ID: <20240221162636.173136-3-thuth@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
To be able to compile QEMU with -Wvla (to prevent potential security
issues), we need to get rid of the variable length array in the
kvmppc_save_htab() function. Replace it with a heap allocation instead.
Message-ID: <20240221162636.173136-2-thuth@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
The Big QEMU Lock (BQL) has many names and they are confusing. The
actual QemuMutex variable is called qemu_global_mutex but it's commonly
referred to as the BQL in discussions and some code comments. The
locking APIs, however, are called qemu_mutex_lock_iothread() and
qemu_mutex_unlock_iothread().
The "iothread" name is historic and comes from when the main thread was
split into into KVM vcpu threads and the "iothread" (now called the main
loop thread). I have contributed to the confusion myself by introducing
a separate --object iothread, a separate concept unrelated to the BQL.
The "iothread" name is no longer appropriate for the BQL. Rename the
locking APIs to:
- void bql_lock(void)
- void bql_unlock(void)
- bool bql_locked(void)
There are more APIs with "iothread" in their names. Subsequent patches
will rename them. There are also comments and documentation that will be
updated in later patches.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Fabiano Rosas <farosas@suse.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Acked-by: Hyman Huang <yong.huang@smartx.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-id: 20240102153529.486531-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
kvm_get_radix_page_info() is only defined for ppc targets (in
target/ppc/kvm.c). The declaration is not useful in other targets,
reduce its scope.
Rename using the 'kvmppc_' prefix following other declarations
from target/ppc/kvm_ppc.h.
Suggested-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20231003070427.69621-2-philmd@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Remove extra 'i' variable to fix this warning :
../target/ppc/kvm.c: In function ‘kvm_arch_put_registers’:
../target/ppc/kvm.c:963:13: warning: declaration of ‘i’ shadows a previous local [-Wshadow=compatible-local]
963 | int i;
| ^
../target/ppc/kvm.c:906:9: note: shadowed declaration is here
906 | int i;
| ^
../target/ppc/kvm.c: In function ‘kvm_arch_get_registers’:
../target/ppc/kvm.c:1265:13: warning: declaration of ‘i’ shadows a previous local [-Wshadow=compatible-local]
1265 | int i;
| ^
../target/ppc/kvm.c:1212:9: note: shadowed declaration is here
1212 | int i, ret;
| ^
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-ID: <20231006053526.1031252-1-clg@kaod.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
It's unnecessary for non-KVM accelerators(TCG, for example),
to call this function, so change the order of kvm_enable() judgment.
The static inline function that returns -1 directly does not work
in TCG's situation.
Signed-off-by: jianchunfu <chunfu.jian@shingroup.cn>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Changes the signature of the target-defined functions for
inserting/removing kvm hw breakpoints. The address and length arguments
are now of vaddr type, which both matches the type used internally in
accel/kvm/kvm-all.c and makes the api target-agnostic.
Signed-off-by: Anton Johansson <anjo@rev.ng>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230807155706.9580-4-anjo@rev.ng>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
kvm_arch_get_default_type() returns the default KVM type. This hook is
particularly useful to derive a KVM type that is valid for "none"
machine model, which is used by libvirt to probe the availability of
KVM.
For MIPS, the existing mips_kvm_type() is reused. This function ensures
the availability of VZ which is mandatory to use KVM on the current
QEMU.
Cc: qemu-stable@nongnu.org
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-id: 20230727073134.134102-2-akihiko.odaki@daynix.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: added doc comment for new function]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
When the Timer Control and Timer Status registers are modified, avoid
calling the KVM backend when not available
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The behaviour of the Address Translation Mode on Interrupt resource is
not consistently supported by all CPU versions or all KVM versions: KVM
HV does not support mode 2, and does not support mode 3 on POWER7 or
early POWER9 processesors. KVM PR only supports mode 0. TCG supports all
modes (0, 2, 3) on CPUs with support for the corresonding LPCR[AIL] mode.
This leads to inconsistencies in guest behaviour and could cause problems
migrating guests.
This was not noticable for Linux guests for a long time because the
kernel only uses modes 0 and 3, and it used to consider AIL-3 to be
advisory in that it would always keep the AIL-0 vectors around, so it
did not matter whether or not interrupts were delivered according to
the AIL mode. Recent Linux guests depend on AIL mode 3 working as
specified in order to support the SCV facility interrupt. If AIL-3 can
not be provided, then H_SET_MODE must return an error to Linux so it can
disable the SCV facility (failure to do so can lead to userspace being
able to crash the guest kernel).
Add the ail-mode-3 capability to specify that AIL-3 is supported. AIL-0
is implied as the baseline, and AIL-2 is no longer supported by spapr.
AIL-2 is not known to be used by any software, but support in TCG could
be restored with an ail-mode-2 capability quite easily if a regression
is reported.
Modify the H_SET_MODE Address Translation Mode on Interrupt resource
handler to check capabilities and correctly return error if not
supported.
KVM has a cap to advertise support for AIL-3.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20230515160216.394612-1-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
The bits in cr reg are grouped into eight 4-bit fields represented
by env->crf[8] and the related calculations should be abstracted to
keep the calling routines simpler to read. This is a step towards
cleaning up the related/calling code for better readability.
Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230503093619.2530487-2-harshpb@linux.ibm.com>
[danielhb: add 'const' modifier to fix linux-user build]
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Several hypervisor capabilities in KVM are target-specific. When exposed
to QEMU users as accelerator properties (i.e. -accel kvm,prop=value), they
should not be available for all targets.
Add a hook for targets to add their own properties to -accel kvm, for
now no such property is defined.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220929072014.20705-3-chenyi.qiang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some systems have /proc/device-tree/cpus/../clock-frequency. However,
this is not the expected path for a CPU device tree directory.
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220712210810.35514-1-muriloo@linux.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
msr_ts macro hides the usage of env->msr, which is a bad
behavior. Substitute it with FIELD_EX64 calls that explicitly use
env->msr as a parameter.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Víctor Colombo <victor.colombo@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220504210541.115256-19-victor.colombo@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
msr_ee macro hides the usage of env->msr, which is a bad behavior
Substitute it with FIELD_EX64 calls that explicitly use env->msr
as a parameter.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Víctor Colombo <victor.colombo@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220504210541.115256-8-victor.colombo@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Init the struct to avoid Valgrind complaints about unitialized bytes,
such as this one:
==39549== Syscall param ioctl(generic) points to uninitialised byte(s)
==39549== at 0x55864E4: ioctl (in /usr/lib64/libc.so.6)
==39549== by 0xD1F7EF: kvm_vm_ioctl (kvm-all.c:3035)
==39549== by 0xAF8F5B: kvm_get_radix_page_info (kvm.c:276)
==39549== by 0xB00533: kvmppc_host_cpu_class_init (kvm.c:2369)
==39549== by 0xD3DCE7: type_initialize (object.c:366)
==39549== by 0xD3FACF: object_class_foreach_tramp (object.c:1071)
==39549== by 0x502757B: g_hash_table_foreach (in /usr/lib64/libglib-2.0.so.0.7000.5)
==39549== by 0xD3FC1B: object_class_foreach (object.c:1093)
==39549== by 0xB0141F: kvm_ppc_register_host_cpu_type (kvm.c:2613)
==39549== by 0xAF87E7: kvm_arch_init (kvm.c:157)
==39549== by 0xD1E2A7: kvm_init (kvm-all.c:2595)
==39549== by 0x8E6E93: accel_init_machine (accel-softmmu.c:39)
==39549== Address 0x1fff00e208 is on thread 1's stack
==39549== in frame #2, created by kvm_get_radix_page_info (kvm.c:267)
==39549== Uninitialised value was created by a stack allocation
==39549== at 0xAF8EE8: kvm_get_radix_page_info (kvm.c:267)
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220331001717.616938-5-danielhb413@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Init 'sregs' to avoid Valgrind complaints about uninitialized bytes
from kvmppc_put_books_sregs():
==54059== Thread 3:
==54059== Syscall param ioctl(generic) points to uninitialised byte(s)
==54059== at 0x55864E4: ioctl (in /usr/lib64/libc.so.6)
==54059== by 0xD1FA23: kvm_vcpu_ioctl (kvm-all.c:3053)
==54059== by 0xAFB18B: kvmppc_put_books_sregs (kvm.c:891)
==54059== by 0xAFB47B: kvm_arch_put_registers (kvm.c:949)
==54059== by 0xD1EDA7: do_kvm_cpu_synchronize_post_init (kvm-all.c:2766)
==54059== by 0x481AF3: process_queued_cpu_work (cpus-common.c:343)
==54059== by 0x4EF247: qemu_wait_io_event_common (cpus.c:412)
==54059== by 0x4EF343: qemu_wait_io_event (cpus.c:436)
==54059== by 0xD21E83: kvm_vcpu_thread_fn (kvm-accel-ops.c:54)
==54059== by 0xFFEBF3: qemu_thread_start (qemu-thread-posix.c:556)
==54059== by 0x54E6DC3: start_thread (in /usr/lib64/libc.so.6)
==54059== by 0x5596C9F: clone (in /usr/lib64/libc.so.6)
==54059== Address 0x799d1cc is on thread 3's stack
==54059== in frame #2, created by kvmppc_put_books_sregs (kvm.c:851)
==54059== Uninitialised value was created by a stack allocation
==54059== at 0xAFAEB0: kvmppc_put_books_sregs (kvm.c:851)
This happens because Valgrind does not consider the 'sregs'
initialization done by kvm_vcpu_ioctl() at the end of the function.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220331001717.616938-4-danielhb413@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
'lpcr' is used as an input of kvm_get_one_reg(). Valgrind doesn't
understand that and it returns warnings as such for this function:
==55240== Thread 1:
==55240== Conditional jump or move depends on uninitialised value(s)
==55240== at 0xB011E4: kvmppc_enable_cap_large_decr (kvm.c:2546)
==55240== by 0x92F28F: cap_large_decr_cpu_apply (spapr_caps.c:523)
==55240== by 0x930C37: spapr_caps_cpu_apply (spapr_caps.c:921)
==55240== by 0x955D3B: spapr_reset_vcpu (spapr_cpu_core.c:73)
==55240== by 0x95612B: spapr_cpu_core_reset (spapr_cpu_core.c:209)
==55240== by 0x95619B: spapr_cpu_core_reset_handler (spapr_cpu_core.c:218)
==55240== by 0xD3605F: qemu_devices_reset (reset.c:69)
==55240== by 0x92112B: spapr_machine_reset (spapr.c:1641)
==55240== by 0x4FBD63: qemu_system_reset (runstate.c:444)
==55240== by 0x62812B: qdev_machine_creation_done (machine.c:1247)
==55240== by 0x5064C3: qemu_machine_creation_done (vl.c:2725)
==55240== by 0x5065DF: qmp_x_exit_preconfig (vl.c:2748)
==55240== Uninitialised value was created by a stack allocation
==55240== at 0xB01158: kvmppc_enable_cap_large_decr (kvm.c:2540)
Init 'lpcr' to avoid this warning.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220331001717.616938-3-danielhb413@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Valgrind isn't convinced that we are initializing the values we assign
to env->spr[spr] because it doesn't understand that the 'val' union is
being written by the kvm_vcpu_ioctl() that follows (via struct
kvm_one_reg).
This results in Valgrind complaining about uninitialized values every
time we use env->spr in a conditional, like this instance:
==707578== Thread 1:
==707578== Conditional jump or move depends on uninitialised value(s)
==707578== at 0xA10A40: hreg_compute_hflags_value (helper_regs.c:106)
==707578== by 0xA10C9F: hreg_compute_hflags (helper_regs.c:173)
==707578== by 0xA110F7: hreg_store_msr (helper_regs.c:262)
==707578== by 0xA051A3: ppc_cpu_reset (cpu_init.c:7168)
==707578== by 0xD4730F: device_transitional_reset (qdev.c:799)
==707578== by 0xD4A11B: resettable_phase_hold (resettable.c:182)
==707578== by 0xD49A77: resettable_assert_reset (resettable.c:60)
==707578== by 0xD4994B: resettable_reset (resettable.c:45)
==707578== by 0xD458BB: device_cold_reset (qdev.c:296)
==707578== by 0x48FBC7: cpu_reset (cpu-common.c:114)
==707578== by 0x97B5EB: spapr_reset_vcpu (spapr_cpu_core.c:38)
==707578== by 0x97BABB: spapr_cpu_core_reset (spapr_cpu_core.c:209)
==707578== Uninitialised value was created by a stack allocation
==707578== at 0xB11F08: kvm_get_one_spr (kvm.c:543)
Initializing 'val' has no impact in the logic and makes Valgrind output
more bearable.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20220331001717.616938-2-danielhb413@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Replace the global variables with inlined helper functions. getpagesize() is very
likely annotated with a "const" function attribute (at least with glibc), and thus
optimization should apply even better.
This avoids the need for a constructor initialization too.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-12-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replace a config-time define with a compile time condition
define (compatible with clang and gcc) that must be declared prior to
its usage. This avoids having a global configure time define, but also
prevents from bad usage, if the config header wasn't included before.
This can help to make some code independent from qemu too.
gcc supports __BYTE_ORDER__ from about 4.6 and clang from 3.2.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[ For the s390x parts I'm involved in ]
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220323155743.1585078-7-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If KVM_CAP_RPT_INVALIDATE KVM capability is enabled, then
- indicate the availability of H_RPT_INVALIDATE hcall to the guest via
ibm,hypertas-functions property.
- Enable the hcall
Both the above are done only if the new sPAPR machine capability
cap-rpt-invalidate is set.
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Message-Id: <20210706112440.1449562-3-bharata@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Each vCPU core exposes its timebase frequency in the DT. When running
under KVM, this means parsing /proc/cpuinfo in order to get the timebase
frequency of the host CPU.
The parsing appears to slow down the boot quite a bit with higher number
of cores:
# of cores seconds spent in spapr_dt_cpus()
8 0.550122
16 1.342375
32 2.850316
64 5.922505
96 9.109224
128 12.245504
256 24.957236
384 37.389113
The timebase frequency of the host CPU is identical for all
cores and it is an invariant for the VM lifetime. Cache it
instead of doing the same expensive parsing again and again.
Rename kvmppc_get_tbfreq() to kvmppc_get_tbfreq_procfs() and
rename the 'retval' variable to make it clear it is used as
fallback only. Come up with a new version of kvmppc_get_tbfreq()
that calls kvmppc_get_tbfreq_procfs() only once and keep the
value in a static.
Zero is certainly not a valid value for the timebase frequency.
Treat atoi() returning zero as another parsing error and return
the fallback value instead. This allows kvmppc_get_tbfreq() to
use zero as an indicator that kvmppc_get_tbfreq_procfs() hasn't
been called yet.
With this patch applied:
384 0.518382
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <161600382766.1780699.6787739229984093959.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
An SEV-ES guest does not allow register state to be altered once it has
been measured. When an SEV-ES guest issues a reboot command, Qemu will
reset the vCPU state and resume the guest. This will cause failures under
SEV-ES. Prevent that from occuring by introducing an arch-specific
callback that returns a boolean indicating whether vCPUs are resettable.
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: David Hildenbrand <david@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Venu Busireddy <venu.busireddy@oracle.com>
Message-Id: <1ac39c441b9a3e970e9556e1cc29d0a0814de6fd.1611682609.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some upcoming POWER machines have a system called PEF (Protected
Execution Facility) which uses a small ultravisor to allow guests to
run in a way that they can't be eavesdropped by the hypervisor. The
effect is roughly similar to AMD SEV, although the mechanisms are
quite different.
Most of the work of this is done between the guest, KVM and the
ultravisor, with little need for involvement by qemu. However qemu
does need to tell KVM to allow secure VMs.
Because the availability of secure mode is a guest visible difference
which depends on having the right hardware and firmware, we don't
enable this by default. In order to run a secure guest you need to
create a "pef-guest" object and set the confidential-guest-support
property to point to it.
Note that this just *allows* secure guests, the architecture of PEF is
such that the guest still needs to talk to the ultravisor to enter
secure mode. Qemu has no direct way of knowing if the guest is in
secure mode, and certainly can't know until well after machine
creation time.
To start a PEF-capable guest, use the command line options:
-object pef-guest,id=pef0 -machine confidential-guest-support=pef0
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
I found that there are many spelling errors in the comments of qemu/target/ppc.
I used spellcheck to check the spelling errors and found some errors in the folder.
Signed-off-by: zhaolichang <zhaolichang@huawei.com>
Reviewed-by: David Edmondson <david.edmondson@oracle.com>
Message-Id: <20201009064449.2336-3-zhaolichang@huawei.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
If kvmppc_load_htab_chunk() fails, its return value is propagated up
to vmstate_load(). It should thus be a negative errno, not -1 (which
maps to EPERM and would lure the user into thinking that the problem
is necessarily related to a lack of privilege).
Return the error reported by KVM or ENOSPC in case of short write.
While here, propagate the error message through an @errp argument
and have the caller to print it with error_report_err() instead
of relying on fprintf().
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <160371604713.305923.5264900354159029580.stgit@bahia.lan>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
QEMU issues the ioctl(KVM_CAP_PPC_FWNMI) on the first vCPU.
If the first vCPU is currently running, the vCPU mutex is held
and the ioctl() cannot be done and waits until the mutex is released.
This never happens and the VM is stuck.
To avoid this deadlock, issue the ioctl on the same vCPU doing the
RTAS call.
The problem can be reproduced by booting a guest with several vCPUs
(the probability to have the problem is (n - 1) / n, n = # of CPUs),
and then by triggering a kernel crash with "echo c >/proc/sysrq-trigger".
On the reboot, the kernel hangs after:
...
[ 0.000000] -----------------------------------------------------
[ 0.000000] ppc64_pft_size = 0x0
[ 0.000000] phys_mem_size = 0x48000000
[ 0.000000] dcache_bsize = 0x80
[ 0.000000] icache_bsize = 0x80
[ 0.000000] cpu_features = 0x0001c06f8f4f91a7
[ 0.000000] possible = 0x0003fbffcf5fb1a7
[ 0.000000] always = 0x00000003800081a1
[ 0.000000] cpu_user_features = 0xdc0065c2 0xaee00000
[ 0.000000] mmu_features = 0x3c006041
[ 0.000000] firmware_features = 0x00000085455a445f
[ 0.000000] physical_start = 0x8000000
[ 0.000000] -----------------------------------------------------
[ 0.000000] numa: NODE_DATA [mem 0x47f33c80-0x47f3ffff]
Fixes: ec010c0066 ("ppc/spapr: KVM FWNMI should not be enabled until guest requests it")
Cc: npiggin@gmail.com
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20200724083533.281700-1-lvivier@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The KVM FWNMI capability should be enabled with the "ibm,nmi-register"
rtas call. Although MCEs from KVM will be delivered as architected
interrupts to the guest before "ibm,nmi-register" is called, KVM has
different behaviour depending on whether the guest has enabled FWNMI
(it attempts to do more recovery on behalf of a non-FWNMI guest).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20200325142906.221248-2-npiggin@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This function calculates the maximum size of the RMA as implied by the
host's page size of structure of the VRMA (there are a number of other
constraints on the RMA size which will supersede this one in many
circumstances).
The current interface takes the current RMA size estimate, and clamps it
to the VRMA derived size. The only current caller passes in an arguably
wrong value (it will match the current RMA estimate in some but not all
cases).
We want to fix that, but for now just keep concerns separated by having the
KVM helper function just return the VRMA derived limit, and let the caller
combine it with other constraints. We call the new function
kvmppc_vrma_limit() to more clearly indicate its limited responsibility.
The helper should only ever be called in the KVM enabled case, so replace
its !CONFIG_KVM stub with an assert() rather than a dummy value.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cedric Le Goater <clg@fr.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Upon a machine check exception (MCE) in a guest address space,
KVM causes a guest exit to enable QEMU to build and pass the
error to the guest in the PAPR defined rtas error log format.
This patch builds the rtas error log, copies it to the rtas_addr
and then invokes the guest registered machine check handler. The
handler in the guest takes suitable action(s) depending on the type
and criticality of the error. For example, if an error is
unrecoverable memory corruption in an application inside the
guest, then the guest kernel sends a SIGBUS to the application.
For recoverable errors, the guest performs recovery actions and
logs the error.
Signed-off-by: Aravinda Prasad <arawinda.p@gmail.com>
[Assume SLOF has allocated enough room for rtas error log]
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20200130184423.20519-5-ganeshgr@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Memory error such as bit flips that cannot be corrected
by hardware are passed on to the kernel for handling.
If the memory address in error belongs to guest then
the guest kernel is responsible for taking suitable action.
Patch [1] enhances KVM to exit guest with exit reason
set to KVM_EXIT_NMI in such cases. This patch handles
KVM_EXIT_NMI exit.
[1] https://www.spinics.net/lists/kvm-ppc/msg12637.html
(e20bbd3d and related commits)
Signed-off-by: Aravinda Prasad <arawinda.p@gmail.com>
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200130184423.20519-4-ganeshgr@linux.ibm.com>
[dwg: #ifdefs to fix compile for 32-bit target]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Introduce fwnmi an spapr capability and add a helper function
which tries to enable it, which would be used by following patch
of the series. This patch by itself does not change the existing
behavior.
Signed-off-by: Aravinda Prasad <arawinda.p@gmail.com>
[eliminate cap_ppc_fwnmi, add fwnmi cap to migration state
and reprhase the commit message]
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20200130184423.20519-3-ganeshgr@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The kvm_handle_debug function can return 0 to go back into the guest
or return 1 to notify the gdbstub thread and pass control to GDB.
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20200110151344.278471-2-farosas@linux.ibm.com>
Tested-by: Leonardo Bras <leonardo@ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
We actually want to access the accelerator, not the machine, so
use the current_accel() wrapper instead.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200121110349.25842-10-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Invoking KVM_SVM_OFF ioctl for TCG guests will lead to a QEMU crash.
Fix this by ensuring that we don't call KVM_SVM_OFF ioctl on TCG.
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Fixes: 4930c1966249 ("ppc/spapr: Support reboot of secure pseries guest")
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Message-Id: <20200102054155.13175-1-bharata@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
A pseries guest can be run as a secure guest on Ultravisor-enabled
POWER platforms. When such a secure guest is reset, we need to
release/reset a few resources both on ultravisor and hypervisor side.
This is achieved by invoking this new ioctl KVM_PPC_SVM_OFF from the
machine reset path.
As part of this ioctl, the secure guest is essentially transitioned
back to normal mode so that it can reboot like a regular guest and
become secure again.
This ioctl has no effect when invoked for a normal guest. If this ioctl
fails for a secure guest, the guest is terminated.
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Message-Id: <20191219031445.8949-3-bharata@linux.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
