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Re: [RFC PATCH-for-8.0 07/10] hw/virtio: Directly access cached VirtIODe
From: |
Greg Kurz |
Subject: |
Re: [RFC PATCH-for-8.0 07/10] hw/virtio: Directly access cached VirtIODevice::access_is_big_endian |
Date: |
Tue, 13 Dec 2022 11:50:19 +0100 |
On Tue, 13 Dec 2022 00:05:14 +0100
Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
> Since the device endianness doesn't change at runtime,
> use the cached value instead of evaluating it on each call.
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
> include/hw/virtio/virtio-access.h | 44 +++++++++++++++----------------
> 1 file changed, 22 insertions(+), 22 deletions(-)
>
> diff --git a/include/hw/virtio/virtio-access.h
> b/include/hw/virtio/virtio-access.h
> index 07aae69042..985f39fe16 100644
> --- a/include/hw/virtio/virtio-access.h
> +++ b/include/hw/virtio/virtio-access.h
> @@ -43,7 +43,7 @@ static inline uint16_t virtio_lduw_phys(VirtIODevice *vdev,
> hwaddr pa)
> {
> AddressSpace *dma_as = vdev->dma_as;
>
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
For x86, virtio_access_is_big_endian() expands to :
static inline bool virtio_access_is_big_endian(VirtIODevice *vdev)
{
return false;
}
When I added these memory accessors, there was a strong requirement from MST
that x86 shouldn't have to pay for an out-of-line check when it is known that
everything is always little endian. Not sure exactly what you're trying to
achieve with VirtIODevice::access_is_big_endian but this shouldn't mess with
this fast path.
> return lduw_be_phys(dma_as, pa);
> }
> return lduw_le_phys(dma_as, pa);
> @@ -53,7 +53,7 @@ static inline uint32_t virtio_ldl_phys(VirtIODevice *vdev,
> hwaddr pa)
> {
> AddressSpace *dma_as = vdev->dma_as;
>
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> return ldl_be_phys(dma_as, pa);
> }
> return ldl_le_phys(dma_as, pa);
> @@ -63,7 +63,7 @@ static inline uint64_t virtio_ldq_phys(VirtIODevice *vdev,
> hwaddr pa)
> {
> AddressSpace *dma_as = vdev->dma_as;
>
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> return ldq_be_phys(dma_as, pa);
> }
> return ldq_le_phys(dma_as, pa);
> @@ -74,7 +74,7 @@ static inline void virtio_stw_phys(VirtIODevice *vdev,
> hwaddr pa,
> {
> AddressSpace *dma_as = vdev->dma_as;
>
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> stw_be_phys(dma_as, pa, value);
> } else {
> stw_le_phys(dma_as, pa, value);
> @@ -86,7 +86,7 @@ static inline void virtio_stl_phys(VirtIODevice *vdev,
> hwaddr pa,
> {
> AddressSpace *dma_as = vdev->dma_as;
>
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> stl_be_phys(dma_as, pa, value);
> } else {
> stl_le_phys(dma_as, pa, value);
> @@ -95,7 +95,7 @@ static inline void virtio_stl_phys(VirtIODevice *vdev,
> hwaddr pa,
>
> static inline void virtio_stw_p(VirtIODevice *vdev, void *ptr, uint16_t v)
> {
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> stw_be_p(ptr, v);
> } else {
> stw_le_p(ptr, v);
> @@ -104,7 +104,7 @@ static inline void virtio_stw_p(VirtIODevice *vdev, void
> *ptr, uint16_t v)
>
> static inline void virtio_stl_p(VirtIODevice *vdev, void *ptr, uint32_t v)
> {
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> stl_be_p(ptr, v);
> } else {
> stl_le_p(ptr, v);
> @@ -113,7 +113,7 @@ static inline void virtio_stl_p(VirtIODevice *vdev, void
> *ptr, uint32_t v)
>
> static inline void virtio_stq_p(VirtIODevice *vdev, void *ptr, uint64_t v)
> {
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> stq_be_p(ptr, v);
> } else {
> stq_le_p(ptr, v);
> @@ -122,7 +122,7 @@ static inline void virtio_stq_p(VirtIODevice *vdev, void
> *ptr, uint64_t v)
>
> static inline int virtio_lduw_p(VirtIODevice *vdev, const void *ptr)
> {
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> return lduw_be_p(ptr);
> } else {
> return lduw_le_p(ptr);
> @@ -131,7 +131,7 @@ static inline int virtio_lduw_p(VirtIODevice *vdev, const
> void *ptr)
>
> static inline int virtio_ldl_p(VirtIODevice *vdev, const void *ptr)
> {
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> return ldl_be_p(ptr);
> } else {
> return ldl_le_p(ptr);
> @@ -140,7 +140,7 @@ static inline int virtio_ldl_p(VirtIODevice *vdev, const
> void *ptr)
>
> static inline uint64_t virtio_ldq_p(VirtIODevice *vdev, const void *ptr)
> {
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> return ldq_be_p(ptr);
> } else {
> return ldq_le_p(ptr);
> @@ -150,9 +150,9 @@ static inline uint64_t virtio_ldq_p(VirtIODevice *vdev,
> const void *ptr)
> static inline uint16_t virtio_tswap16(VirtIODevice *vdev, uint16_t s)
> {
> #if HOST_BIG_ENDIAN
> - return virtio_access_is_big_endian(vdev) ? s : bswap16(s);
> + return vdev->access_is_big_endian ? s : bswap16(s);
> #else
> - return virtio_access_is_big_endian(vdev) ? bswap16(s) : s;
> + return vdev->access_is_big_endian ? bswap16(s) : s;
> #endif
> }
>
> @@ -160,7 +160,7 @@ static inline uint16_t
> virtio_lduw_phys_cached(VirtIODevice *vdev,
> MemoryRegionCache *cache,
> hwaddr pa)
> {
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> return lduw_be_phys_cached(cache, pa);
> }
> return lduw_le_phys_cached(cache, pa);
> @@ -170,7 +170,7 @@ static inline uint32_t
> virtio_ldl_phys_cached(VirtIODevice *vdev,
> MemoryRegionCache *cache,
> hwaddr pa)
> {
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> return ldl_be_phys_cached(cache, pa);
> }
> return ldl_le_phys_cached(cache, pa);
> @@ -180,7 +180,7 @@ static inline uint64_t
> virtio_ldq_phys_cached(VirtIODevice *vdev,
> MemoryRegionCache *cache,
> hwaddr pa)
> {
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> return ldq_be_phys_cached(cache, pa);
> }
> return ldq_le_phys_cached(cache, pa);
> @@ -190,7 +190,7 @@ static inline void virtio_stw_phys_cached(VirtIODevice
> *vdev,
> MemoryRegionCache *cache,
> hwaddr pa, uint16_t value)
> {
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> stw_be_phys_cached(cache, pa, value);
> } else {
> stw_le_phys_cached(cache, pa, value);
> @@ -201,7 +201,7 @@ static inline void virtio_stl_phys_cached(VirtIODevice
> *vdev,
> MemoryRegionCache *cache,
> hwaddr pa, uint32_t value)
> {
> - if (virtio_access_is_big_endian(vdev)) {
> + if (vdev->access_is_big_endian) {
> stl_be_phys_cached(cache, pa, value);
> } else {
> stl_le_phys_cached(cache, pa, value);
> @@ -216,9 +216,9 @@ static inline void virtio_tswap16s(VirtIODevice *vdev,
> uint16_t *s)
> static inline uint32_t virtio_tswap32(VirtIODevice *vdev, uint32_t s)
> {
> #if HOST_BIG_ENDIAN
> - return virtio_access_is_big_endian(vdev) ? s : bswap32(s);
> + return vdev->access_is_big_endian ? s : bswap32(s);
> #else
> - return virtio_access_is_big_endian(vdev) ? bswap32(s) : s;
> + return vdev->access_is_big_endian ? bswap32(s) : s;
> #endif
> }
>
> @@ -230,9 +230,9 @@ static inline void virtio_tswap32s(VirtIODevice *vdev,
> uint32_t *s)
> static inline uint64_t virtio_tswap64(VirtIODevice *vdev, uint64_t s)
> {
> #if HOST_BIG_ENDIAN
> - return virtio_access_is_big_endian(vdev) ? s : bswap64(s);
> + return vdev->access_is_big_endian ? s : bswap64(s);
> #else
> - return virtio_access_is_big_endian(vdev) ? bswap64(s) : s;
> + return vdev->access_is_big_endian ? bswap64(s) : s;
> #endif
> }
>
- [PATCH-for-8.0 05/10] hw/virtio: Extract QMP related code virtio-qmp.c, (continued)
[RFC PATCH-for-8.0 07/10] hw/virtio: Directly access cached VirtIODevice::access_is_big_endian, Philippe Mathieu-Daudé, 2022/12/12
- Re: [RFC PATCH-for-8.0 07/10] hw/virtio: Directly access cached VirtIODevice::access_is_big_endian,
Greg Kurz <=
[PATCH-for-8.0 08/10] hw/virtio: Un-inline virtio_access_is_big_endian(), Philippe Mathieu-Daudé, 2022/12/12
[RFC PATCH-for-8.0 09/10] hw/virtio: Extract vhost_user_ram_slots_max() to vhost-user-target.c, Philippe Mathieu-Daudé, 2022/12/12
[RFC PATCH-for-8.0 10/10] hw/virtio: Make most of virtio devices target-independent, Philippe Mathieu-Daudé, 2022/12/12