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2022-04-06Replace TARGET_WORDS_BIGENDIANMarc-André Lureau
Convert the TARGET_WORDS_BIGENDIAN macro, similarly to what was done with HOST_BIG_ENDIAN. The new TARGET_BIG_ENDIAN macro is either 0 or 1, and thus should always be defined to prevent misuse. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Suggested-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20220323155743.1585078-8-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06Replace config-time define HOST_WORDS_BIGENDIANMarc-André Lureau
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>
2019-08-16include: Make headers more self-containedMarkus Armbruster
Back in 2016, we discussed[1] rules for headers, and these were generally liked: 1. Have a carefully curated header that's included everywhere first. We got that already thanks to Peter: osdep.h. 2. Headers should normally include everything they need beyond osdep.h. If exceptions are needed for some reason, they must be documented in the header. If all that's needed from a header is typedefs, put those into qemu/typedefs.h instead of including the header. 3. Cyclic inclusion is forbidden. This patch gets include/ closer to obeying 2. It's actually extracted from my "[RFC] Baby steps towards saner headers" series[2], which demonstrates a possible path towards checking 2 automatically. It passes the RFC test there. [1] Message-ID: <87h9g8j57d.fsf@blackfin.pond.sub.org> https://lists.nongnu.org/archive/html/qemu-devel/2016-03/msg03345.html [2] Message-Id: <20190711122827.18970-1-armbru@redhat.com> https://lists.nongnu.org/archive/html/qemu-devel/2019-07/msg02715.html Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-Id: <20190812052359.30071-2-armbru@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2018-06-01hw: Do not include "exec/address-spaces.h" if it is not necessaryPhilippe Mathieu-Daudé
Code change produced with: $ git grep '#include "exec/address-spaces.h"' hw include/hw | \ cut -d: -f-1 | \ xargs egrep -L "(get_system_|address_space_)" | \ xargs sed -i.bak '/#include "exec\/address-spaces.h"/d' Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20180528232719.4721-12-f4bug@amsat.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-02-17virtio: add virtio_*_phys_cachedPaolo Bonzini
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-01-10virtio: convert to use DMA apiJason Wang
Currently, all virtio devices bypass IOMMU completely. This is because address_space_memory is assumed and used during DMA emulation. This patch converts the virtio core API to use DMA API. This idea is - introducing a new transport specific helper to query the dma address space. (only pci version is implemented). - query and use this address space during virtio device guest memory accessing when iommu platform (VIRTIO_F_IOMMU_PLATFORM) was enabled for this device. Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Kevin Wolf <kwolf@redhat.com> Cc: Amit Shah <amit.shah@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: qemu-block@nongnu.org Signed-off-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-07-12Clean up ill-advised or unusual header guardsMarkus Armbruster
Cleaned up with scripts/clean-header-guards.pl. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-06-07virtio: move bi-endian target support to a single locationGreg Kurz
Paolo's recent cpu.h cleanups broke legacy virtio for ppc64 LE guests (and arm BE guests as well, even if I have not verified that). Especially, commit "33c11879fd42 qemu-common: push cpu.h inclusion out of qemu-common.h" has the side-effect of silently hiding the TARGET_IS_BIENDIAN macro from the virtio memory accessors, and thus fully disabling support of endian changing targets. To be sure this cannot happen again, let's gather all the bi-endian bits where they belong in include/hw/virtio/virtio-access.h. The changes in hw/virtio/vhost.c are safe because vhost_needs_vring_endian() is not called on a hot path and non bi-endian targets will return false anyway. While here, also rename TARGET_IS_BIENDIAN to be more precise: it is only for legacy virtio and bi-endian guests. Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16virtio: optimize virtio_access_is_big_endian() for little-endian targetsGreg Kurz
When adding cross-endian support, we introduced the TARGET_IS_BIENDIAN macro and the virtio_access_is_big_endian() helper to have a branchless fast path in the virtio memory accessors for targets that don't switch endian. This was considered as a strong requirement at the time. Now we have added a runtime check for virtio 1.0, which ruins the benefit of the virtio_access_is_big_endian() helper for always little-endian targets. With this patch, always little-endian targets stop checking for virtio 1.0, since the result is little-endian in all cases. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com>
2016-02-16virtio: move cross-endian helper to vhostGreg Kurz
If target is bi-endian (ppc64, arm), the virtio_legacy_is_cross_endian() indeed returns the runtime state of the virtio device. However, it returns false unconditionally in the general case. This sounds a bit strange given the name of the function. This helper is only useful for vhost actually, where indeed non bi-endian targets don't have to deal with cross-endian issues. This patch moves the helper to vhost.c and gives it a more appropriate name. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com>
2016-02-16virtio-net: use the backend cross-endian capabilitiesGreg Kurz
When running a fully emulated device in cross-endian conditions, including a virtio 1.0 device offered to a big endian guest, we need to fix the vnet headers. This is currently handled by the virtio_net_hdr_swap() function in the core virtio-net code but it should actually be handled by the net backend. With this patch, virtio-net now tries to configure the backend to do the endian fixing when the device starts (i.e. drivers sets the CONFIG_OK bit). If the backend cannot support the requested endiannes, we have to fallback onto virtio_net_hdr_swap(): this is recorded in the needs_vnet_hdr_swap flag, to be used in the TX and RX paths. Note that we reset the backend to the default behaviour (guest native endianness) when the device stops (i.e. device status had CONFIG_OK bit and driver unsets it). This is needed, with the linux tap backend at least, otherwise the guest may lose network connectivity if rebooted into a different endianness. The current vhost-net code also tries to configure net backends. This will be no more needed and will be reverted in a subsequent patch. Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com>
2015-09-10virtio: avoid leading underscores for helpersCornelia Huck
Commit ef546f1275f6563e8934dd5e338d29d9f9909ca6 ("virtio: add feature checking helpers") introduced a helper __virtio_has_feature. We don't want to use reserved identifiers, though, so let's rename __virtio_has_feature to virtio_has_feature and virtio_has_feature to virtio_vdev_has_feature. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-07-20virtio-net: unbreak any layoutJason Wang
Commit 032a74a1c0fcdd5fd1c69e56126b4c857ee36611 ("virtio-net: byteswap virtio-net header") breaks any layout by requiring out_sg[0].iov_len >= n->guest_hdr_len. Fixing this by copying header to temporary buffer if swap is needed, and then use this buffer as part of out_sg. Fixes 032a74a1c0fcdd5fd1c69e56126b4c857ee36611 ("virtio-net: byteswap virtio-net header") Cc: qemu-stable@nongnu.org Cc: clg@fr.ibm.com Signed-off-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-06-17virtio: introduce virtio_legacy_is_cross_endian()Greg Kurz
This helper will be used by vhost and tap to detect cross-endianness in the legacy virtio case. Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-06-10virtio: endianness checks for virtio 1.0 devicesCornelia Huck
Add code that checks for the VERSION_1 feature bit in order to make decisions about the device's endianness. This allows us to support transitional devices. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
2014-06-29virtio: memory accessors for endian-ambivalent targetsGreg Kurz
This is the virtio-access.h header file taken from Rusty's "endian-ambivalent targets using legacy virtio" patch. It introduces helpers that should be used when accessing vring data or by drivers for data that contains headers. The virtio config space is also target endian, but the current code already handles that with the virtio_is_big_endian() helper. There is no obvious benefit at using the virtio accessors in this case. Now we have two distinct paths: a fast inline one for fixed endian targets, and a slow out-of-line one for targets that define the new TARGET_IS_BIENDIAN macro. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> [ relicensed virtio-access.h to GPLv2+ on Rusty's request, pass &address_space_memory to physical memory accessors, per-device endianness, virtio tswap16 and tswap64 helpers, faspath for fixed endian targets, Greg Kurz <gkurz@linux.vnet.ibm.com> ] Cc: Cédric Le Goater <clg@fr.ibm.com> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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