Commit graph

28988 commits

Author SHA1 Message Date
Marc-André Lureau
4a32844433 meson: convert hw/pci
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:28 -04:00
Marc-André Lureau
ea7e9b5730 meson: convert hw/pci-bridge
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:28 -04:00
Marc-André Lureau
9235a82d0f meson: convert hw/pci-host
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:28 -04:00
Marc-André Lureau
00953fa550 meson: convert hw/pcmcia
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:28 -04:00
Marc-André Lureau
7633d84436 meson: convert hw/scsi
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:28 -04:00
Marc-André Lureau
092795f858 meson: convert hw/sd
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:27 -04:00
Marc-André Lureau
b1bc817d68 meson: convert hw/ssi
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:27 -04:00
Paolo Bonzini
ee80237e38 meson: convert hw/rtc
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:27 -04:00
Paolo Bonzini
beeb0566d7 meson: convert hw/timer
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:27 -04:00
Paolo Bonzini
70c2cfedd3 meson: convert hw/tpm
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:27 -04:00
Paolo Bonzini
06677ce161 meson: convert hw/usb
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:26 -04:00
Marc-André Lureau
4f780d5629 meson: convert hw/vfio
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:26 -04:00
Marc-André Lureau
be786d2f4a meson: convert hw/virtio
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:26 -04:00
Marc-André Lureau
e4fea7db5e meson: convert hw/watchdog
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:26 -04:00
Marc-André Lureau
97813b940d meson: convert hw/mem
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:26 -04:00
Marc-André Lureau
d6c9b1f003 meson: convert hw/smbios
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:25 -04:00
Paolo Bonzini
b908c370f7 meson: convert hw/nubus
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:25 -04:00
Paolo Bonzini
56d996c50a meson: convert hw/semihosting
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:25 -04:00
Marc-André Lureau
c92a309777 meson: convert hw/core
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:25 -04:00
Marc-André Lureau
582ea95f5f meson: convert hw/xen
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:24 -04:00
Paolo Bonzini
2becc36a3e meson: infrastructure for building emulators
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:30:17 -04:00
Paolo Bonzini
243af0225a trace: switch position of headers to what Meson requires
Meson doesn't enjoy the same flexibility we have with Make in choosing
the include path.  In particular the tracing headers are using
$(build_root)/$(<D).

In order to keep the include directives unchanged,
the simplest solution is to generate headers with patterns like
"trace/trace-audio.h" and place forwarding headers in the source tree
such that for example "audio/trace.h" includes "trace/trace-audio.h".

This patch is too ugly to be applied to the Makefiles now.  It's only
a way to separate the changes to the tracing header files from the
Meson rewrite of the tracing logic.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-08-21 06:18:24 -04:00
Cornelia Huck
3ff3c5d317 hw: add compat machines for 5.2
Add 5.2 machine types for arm/i440fx/q35/s390x/spapr.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200819144016.281156-1-cohuck@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-08-19 10:45:48 -04:00
Michal Privoznik
c556600598 qmp: Expose MachineClass::default_ram_id
If a management application (like Libvirt) want's to preserve
migration ability and switch to '-machine memory-backend' it
needs to set exactly the same RAM id as QEMU would. Since the id
is machine type dependant, expose it under 'query-machines'
result. Some machine types don't have the attribute set (riscv
family for example), therefore the QMP attribute must be
optional.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Message-Id: <9384422f63fe594a54d801f9cb4539b1d2ce9b67.1590481402.git.mprivozn@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
[ehabkost: updated doc to "since 5.2"]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-08-19 10:45:21 -04:00
Greg Kurz
3110f0ee19 spapr/xive: Use xive_source_esb_len()
static inline size_t xive_source_esb_len(XiveSource *xsrc)
{
    return (1ull << xsrc->esb_shift) * xsrc->nr_irqs;
}

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159733969034.320580.6571451425779179477.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-14 13:35:45 +10:00
Greg Kurz
37035df51e nvram: Exit QEMU if NVRAM cannot contain all -prom-env data
Since commit 61f20b9dc5 ("spapr_nvram: Pre-initialize the NVRAM to
support the -prom-env parameter"), pseries machines can pre-initialize
the "system" partition in the NVRAM with the data passed to all -prom-env
parameters on the QEMU command line.

In this case it is assumed that all the data fits in 64 KiB, but the user
can easily pass more and crash QEMU:

$ qemu-system-ppc64 -M pseries $(for ((x=0;x<128;x++)); do \
  echo -n " -prom-env " ; printf "%0.sx" {1..1024}; \
  done) # this requires ~128 Kib
malloc(): corrupted top size
Aborted (core dumped)

This happens because we don't check if all the prom-env data fits in
the NVRAM and chrp_nvram_set_var() happily memcpy() it passed the
buffer.

This crash affects basically all ppc/ppc64 machine types that use -prom-env:
- pseries (all versions)
- g3beige
- mac99

and also sparc/sparc64 machine types:
- LX
- SPARCClassic
- SPARCbook
- SS-10
- SS-20
- SS-4
- SS-5
- SS-600MP
- Voyager
- sun4u
- sun4v

Add a max_len argument to chrp_nvram_create_system_partition() so that
it can check the available size before writing to memory.

Since NVRAM is populated at machine init, it seems reasonable to consider
this error as fatal. So, instead of reporting an error when we detect that
the NVRAM is too small and adapt all machine types to handle it, we simply
exit QEMU in all cases. This is still better than crashing. If someone
wants another behavior, I guess this can be reworked later.

Tested with:

$ yes q | \
  (for arch in ppc ppc64 sparc sparc64; do \
       echo == $arch ==; \
       qemu=${arch}-softmmu/qemu-system-$arch; \
       for mach in $($qemu -M help | awk '! /^Supported/ { print $1 }'); do \
           echo $mach; \
           $qemu -M $mach -monitor stdio -nodefaults -nographic \
           $(for ((x=0;x<128;x++)); do \
                 echo -n " -prom-env " ; printf "%0.sx" {1..1024}; \
             done) >/dev/null; \
        done; echo; \
   done)

Without the patch, affected machine types cause QEMU to report some
memory corruption and crash:

malloc(): corrupted top size

free(): invalid size

*** stack smashing detected ***: terminated

With the patch, QEMU prints the following message and exits:

NVRAM is too small. Try to pass less data to -prom-env

It seems that the conditions for the crash have always existed, but it
affects pseries, the machine type I care for, since commit 61f20b9dc5
only.

Fixes: 61f20b9dc5 ("spapr_nvram: Pre-initialize the NVRAM to support the -prom-env parameter")
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1867739
Reported-by: John Snow <jsnow@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159736033937.350502.12402444542194031035.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-14 13:34:31 +10:00
Greg Kurz
1118b6b727 spapr/xive: Simplify error handling of kvmppc_xive_cpu_synchronize_state()
Now that kvmppc_xive_cpu_get_state() returns negative on error, use that
and get rid of the temporary Error object and error_propagate().

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159707852916.1489912.8376334685349668124.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:09:38 +10:00
Greg Kurz
61203f2b35 ppc/xive: Simplify error handling in xive_tctx_realize()
Now that kvmppc_xive_cpu_connect() returns a negative errno on failure,
use that and get rid of the local_err boilerplate.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159707852234.1489912.16410314514265848075.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:07:28 +10:00
Greg Kurz
6cdc0e2063 spapr/xive: Simplify error handling in kvmppc_xive_connect()
Now that all these functions return a negative errno on failure, check
that and get rid of the local_err boilerplate.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159707851537.1489912.1030839306195472651.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:06:44 +10:00
Greg Kurz
2a8100cb61 ppc/xive: Fix error handling in vmstate_xive_tctx_*() callbacks
Now that kvmppc_xive_cpu_get_state() and kvmppc_xive_cpu_set_state()
return negative errnos on failures, use that instead local_err because
it is the recommended practice. Also return that instead of -1 since
vmstate expects negative errnos.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159707850840.1489912.14912810818646455474.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:05:06 +10:00
Greg Kurz
a845a54cbe spapr/xive: Fix error handling in kvmppc_xive_post_load()
Now that all these functions return a negative errno on failure, check
that because it is preferred to local_err. And most of all, propagate it
because vmstate expects negative errnos.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159707850148.1489912.18355118622296682631.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:04:05 +10:00
Greg Kurz
42a92d925d spapr/kvm: Fix error handling in kvmppc_xive_pre_save()
Now that kvmppc_xive_get_queues() returns a negative errno on failure, check
with that because it is preferred to local_err. And most of all, propagate
it because vmstate expects negative errnos.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159707849455.1489912.6034461176847728064.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:03:35 +10:00
Greg Kurz
d55daadcb8 spapr/xive: Rework error handling of kvmppc_xive_set_source_config()
Since kvm_device_access() returns a negative errno on failure, convert
kvmppc_xive_set_source_config() to use it for error checking. This allows
to get rid of the local_err boilerplate.

Propagate the return value so that callers may use it as well to check
failures.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159707848764.1489912.17078842252160674523.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:00:52 +10:00
Greg Kurz
d53482a73b spapr/xive: Rework error handling in kvmppc_xive_get_queues()
Since kvmppc_xive_get_queue_config() has a return value, convert
kvmppc_xive_get_queues() to use it for error checking. This allows
to get rid of the local_err boiler plate.

Propagate the return value so that callers may use it as well to check
failures.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159707848069.1489912.14879208798696134531.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:00:52 +10:00
Greg Kurz
f9a548edf2 spapr/xive: Rework error handling of kvmppc_xive_[gs]et_queue_config()
Since kvm_device_access() returns a negative errno on failure, convert
kvmppc_xive_get_queue_config() and kvmppc_xive_set_queue_config() to
use it for error checking. This allows to get rid of the local_err
boilerplate.

Propagate the return value so that callers may use it as well to check
failures.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159707847357.1489912.2032291280645236480.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:00:52 +10:00
Greg Kurz
5fa36b7ffb spapr/xive: Rework error handling of kvmppc_xive_cpu_[gs]et_state()
kvm_set_one_reg() returns a negative errno on failure, use that instead
of errno. Also propagate it to callers so they can use it to check
for failures and hopefully get rid of their local_err boilerplate.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159707846665.1489912.14267225652103441921.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:00:52 +10:00
Greg Kurz
b14adb4a27 spapr/xive: Rework error handling of kvmppc_xive_mmap()
Callers currently check failures of kvmppc_xive_mmap() through the
@errp argument, which isn't a recommanded practice. It is preferred
to use a return value when possible.

Since NULL isn't an invalid address in theory, it seems better to
return MAP_FAILED and to teach callers to handle it.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159707845972.1489912.719896767746375765.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:00:52 +10:00
Greg Kurz
46407a2531 spapr/xive: Rework error handling of kvmppc_xive_source_reset()
Since kvmppc_xive_source_reset_one() has a return value, convert
kvmppc_xive_source_reset() to use it for error checking. This
allows to get rid of the local_err boiler plate.

Propagate the return value so that callers may use it as well to check
failures.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159707845245.1489912.9151822670764690034.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:00:52 +10:00
Greg Kurz
3885ca6688 spapr/xive: Rework error handling of kvmppc_xive_cpu_connect()
Use error_setg_errno() instead of error_setg(strerror()). While here,
use -ret instead of errno since kvm_vcpu_enable_cap() returns a negative
errno on failure.

Use ERRP_GUARD() to ensure that errp can be passed to error_append_hint(),
and get rid of the local_err boilerplate.

Propagate the return value so that callers may use it as well to check
failures.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159707844549.1489912.4862921680328017645.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:00:52 +10:00
Greg Kurz
4a6891b838 spapr: Simplify error handling in spapr_phb_realize()
The spapr_phb_realize() function has a local_err variable which
is used to:

1) check failures of spapr_irq_findone() and spapr_irq_claim()

2) prepend extra information to the error message

Recent work from Markus Armbruster highlighted we get better
code when testing the return value of a function, rather than
setting up all the local_err boiler plate. For similar reasons,
it is now preferred to use ERRP_GUARD() and error_prepend()
rather than error_propagate_prepend().

Since spapr_irq_findone() and spapr_irq_claim() return negative
values in case of failure, do both changes.

This is just cleanup, no functional impact.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <159707843851.1489912.6108405733810934642.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 21:00:52 +10:00
Greg Kurz
a490711934 spapr/xive: Convert KVM device fd checks to assert()
All callers guard these functions with an xive_in_kernel() helper. Make
it clear that they are only to be called when the KVM XIVE device exists.

Note that the check on xive is dropped in kvmppc_xive_disconnect(). It
really cannot be NULL since it comes from set_active_intc() which only
passes pointers to allocated objects.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <159679994169.876294.11026653581505077112.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 20:58:52 +10:00
Greg Kurz
e519cdd9bc ppc/xive: Introduce dedicated kvm_irqchip_in_kernel() wrappers
Calls to the KVM XIVE device are guarded by kvm_irqchip_in_kernel(). This
ensures that QEMU won't try to use the device if KVM is disabled or if
an in-kernel irqchip isn't required.

When using ic-mode=dual with the pseries machine, we have two possible
interrupt controllers: XIVE and XICS. The kvm_irqchip_in_kernel() helper
will return true as soon as any of the KVM device is created. It might
lure QEMU to think that the other one is also around, while it is not.
This is exactly what happens with ic-mode=dual at machine init when
claiming IRQ numbers, which must be done on all possible IRQ backends,
eg. RTAS event sources or the PHB0 LSI table : only the KVM XICS device
is active but we end up calling kvmppc_xive_source_reset_one() anyway,
which fails. This doesn't cause any trouble because of another bug :
kvmppc_xive_source_reset_one() lacks an error_setg() and callers don't
see the failure.

Most of the other kvmppc_xive_* functions have similar xive->fd
checks to filter out the case when KVM XIVE isn't active. It
might look safer to have idempotent functions but it doesn't
really help to understand what's going on when debugging.

Since we already have all the kvm_irqchip_in_kernel() in place,
also have the callers to check xive->fd as well before calling
KVM XIVE specific code. This is straight-forward for the spapr
specific XIVE code. Some more care is needed for the platform
agnostic XIVE code since it cannot access xive->fd directly.
Introduce new in_kernel() methods in some base XIVE classes
for this purpose and implement them only in spapr.

In all cases, we still need to call kvm_irqchip_in_kernel() so that
compilers can optimize the kvmppc_xive_* calls away when CONFIG_KVM
isn't defined, thus avoiding the need for stubs.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159679993438.876294.7285654331498605426.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 20:56:01 +10:00
Greg Kurz
cf36e5b376 ppc/xive: Rework setup of XiveSource::esb_mmio
Depending on whether XIVE is emultated or backed with a KVM XIVE device,
the ESB MMIOs of a XIVE source point to an I/O memory region or a mapped
memory region.

This is currently handled by checking kvm_irqchip_in_kernel() returns
false in xive_source_realize(). This is a bit awkward as we usually
need to do extra things when we're using the in-kernel backend, not
less. But most important, we can do better: turn the existing "xive.esb"
memory region into a plain container, introduce an "xive.esb-emulated"
I/O subregion and rename the existing "xive.esb" subregion in the KVM
code to "xive.esb-kvm". Since "xive.esb-kvm" is added with overlap
and a higher priority, it prevails over "xive.esb-emulated" (ie.
a guest using KVM XIVE will interact with "xive.esb-kvm" instead of
the default "xive.esb-emulated" region.

While here, consolidate the computation of the MMIO region size in
a common helper.

Suggested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159679992680.876294.7520540158586170894.stgit@bahia.lan>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-13 20:50:17 +10:00
Christian Schoenebeck
da9f2eda25 9pfs: clarify latency of v9fs_co_run_in_worker()
As we just fixed a severe performance issue with Treaddir request
handling, clarify this overall issue as a comment on
v9fs_co_run_in_worker() with the intention to hopefully prevent
such performance mistakes in future (and fixing other yet
outstanding ones).

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <4d34d332e1aaa8a2cf8dc0b5da4fd7727f2a86e8.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-08-12 09:17:32 +02:00
Christian Schoenebeck
d2c5cf7ca1 9pfs: differentiate readdir lock between 9P2000.u vs. 9P2000.L
Previous patch suggests that it might make sense to use a different mutex
type now while handling readdir requests, depending on the precise
protocol variant, as v9fs_do_readdir_with_stat() (used by 9P2000.u) uses
a CoMutex to avoid deadlocks that might happen with QemuMutex otherwise,
whereas do_readdir_many() (used by 9P2000.L) should better use a
QemuMutex, as the precise behaviour of a failed CoMutex lock on fs driver
side would not be clear.

And to avoid the wrong lock type being used, be now strict and error out
if a 9P2000.L client sends a Tread on a directory, and likeweise error out
if a 9P2000.u client sends a Treaddir request.

This patch is just intended as transitional measure, as currently 9P2000.u
vs. 9P2000.L implementations currently differ where the main logic of
fetching directory entries is located at (9P2000.u still being more top
half focused, while 9P2000.L already being bottom half focused in regards
to fetching directory entries that is).

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <9a2ddc347e533b0d801866afd9dfac853d2d4106.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-08-12 09:17:32 +02:00
Christian Schoenebeck
0c4356ba7d 9pfs: T_readdir latency optimization
Make top half really top half and bottom half really bottom half:

Each T_readdir request handling is hopping between threads (main
I/O thread and background I/O driver threads) several times for
every individual directory entry, which sums up to huge latencies
for handling just a single T_readdir request.

Instead of doing that, collect now all required directory entries
(including all potentially required stat buffers for each entry) in
one rush on a background I/O thread from fs driver by calling the
previously added function v9fs_co_readdir_many() instead of
v9fs_co_readdir(), then assemble the entire resulting network
response message for the readdir request on main I/O thread. The
fs driver is still aborting the directory entry retrieval loop
(on the background I/O thread inside of v9fs_co_readdir_many())
as soon as it would exceed the client's requested maximum R_readdir
response size. So this will not introduce a performance penalty on
another end.

Also: No longer seek initial directory position in v9fs_readdir(),
as this is now handled (more consistently) by
v9fs_co_readdir_many() instead.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <c7c3d1cf4e86611538cef44897842819d9359d7a.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-08-12 09:17:32 +02:00
Christian Schoenebeck
2149675b19 9pfs: add new function v9fs_co_readdir_many()
The newly added function v9fs_co_readdir_many() retrieves multiple
directory entries with a single fs driver request. It is intended to
replace uses of v9fs_co_readdir(), the latter only retrieves a
single directory entry per fs driver request instead.

The reason for this planned replacement is that for every fs driver
request the coroutine is dispatched from main I/O thread to a
background I/O thread and eventually dispatched back to main I/O
thread. Hopping between threads adds latency. So if a 9pfs Treaddir
request reads a large amount of directory entries, this currently
sums up to huge latencies of several hundred ms or even more. So
using v9fs_co_readdir_many() instead of v9fs_co_readdir() will
provide significant performance improvements.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <73dc827a12ef577ae7e644dcf34a5c0e443ab42f.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-08-12 09:17:32 +02:00
Christian Schoenebeck
dd8151f4fe 9pfs: split out fs driver core of v9fs_co_readdir()
The implementation of v9fs_co_readdir() has two parts: the outer
part is executed by main I/O thread, whereas the inner part is
executed by fs driver on a background I/O thread.

Move the inner part to its own new, private function do_readdir(),
so it can be shared by another upcoming new function.

This is just a preparatory patch for the subsequent patch, with the
purpose to avoid the next patch to clutter the overall diff.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <a426ee06e77584fa2d8253ce5d8bea519eb3ffd4.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-08-12 09:17:32 +02:00
Christian Schoenebeck
29c9d2ca80 9pfs: make v9fs_readdir_response_size() public
Rename function v9fs_readdir_data_size() -> v9fs_readdir_response_size()
and make it callable from other units. So far this function is only
used by 9p.c, however subsequent patches require the function to be
callable from another 9pfs unit. And as we're at it; also make it clear
for what this function is used for.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <3668ebc7d5b929a0e4f1357457060d96f50f76f4.1596012787.git.qemu_oss@crudebyte.com>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
2020-08-12 09:17:32 +02:00
Greg Kurz
e781139539 spapr/xive: Simplify kvmppc_xive_disconnect()
Since this function begins with:

    /* The KVM XIVE device is not in use */
    if (!xive || xive->fd == -1) {
        return;
    }

we obviously don't need to check xive->fd again.

Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <159673297296.766512.14780055521619233656.stgit@bahia.lan>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2020-08-12 13:16:27 +10:00