219af7331f
Our QA reported a problem caused by movntdqa instructions. Currently, the KVM hypervisor doesn't support VEX-prefix instructions emulation. If users passthrough a GPU to guest with vfio option 'x-no-mmap=on', then all access to the BARs will be trapped and emulated. The KVM hypervisor would raise an inertal error to qemu which cause the guest killed. (Since 'movntdqa' ins is not supported.) This patch try not to enable movntdqa optimization if the driver is running in hypervisor guest. Signed-off-by: Changbin Du <changbin.du@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/1513924309-3113-1-git-send-email-changbin.du@intel.com Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
107 lines
3.1 KiB
C
107 lines
3.1 KiB
C
/*
|
|
* Copyright © 2016 Intel Corporation
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a
|
|
* copy of this software and associated documentation files (the "Software"),
|
|
* to deal in the Software without restriction, including without limitation
|
|
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
|
* and/or sell copies of the Software, and to permit persons to whom the
|
|
* Software is furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice (including the next
|
|
* paragraph) shall be included in all copies or substantial portions of the
|
|
* Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
|
|
* IN THE SOFTWARE.
|
|
*
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <asm/fpu/api.h>
|
|
|
|
#include "i915_drv.h"
|
|
|
|
static DEFINE_STATIC_KEY_FALSE(has_movntdqa);
|
|
|
|
#ifdef CONFIG_AS_MOVNTDQA
|
|
static void __memcpy_ntdqa(void *dst, const void *src, unsigned long len)
|
|
{
|
|
kernel_fpu_begin();
|
|
|
|
len >>= 4;
|
|
while (len >= 4) {
|
|
asm("movntdqa (%0), %%xmm0\n"
|
|
"movntdqa 16(%0), %%xmm1\n"
|
|
"movntdqa 32(%0), %%xmm2\n"
|
|
"movntdqa 48(%0), %%xmm3\n"
|
|
"movaps %%xmm0, (%1)\n"
|
|
"movaps %%xmm1, 16(%1)\n"
|
|
"movaps %%xmm2, 32(%1)\n"
|
|
"movaps %%xmm3, 48(%1)\n"
|
|
:: "r" (src), "r" (dst) : "memory");
|
|
src += 64;
|
|
dst += 64;
|
|
len -= 4;
|
|
}
|
|
while (len--) {
|
|
asm("movntdqa (%0), %%xmm0\n"
|
|
"movaps %%xmm0, (%1)\n"
|
|
:: "r" (src), "r" (dst) : "memory");
|
|
src += 16;
|
|
dst += 16;
|
|
}
|
|
|
|
kernel_fpu_end();
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* i915_memcpy_from_wc: perform an accelerated *aligned* read from WC
|
|
* @dst: destination pointer
|
|
* @src: source pointer
|
|
* @len: how many bytes to copy
|
|
*
|
|
* i915_memcpy_from_wc copies @len bytes from @src to @dst using
|
|
* non-temporal instructions where available. Note that all arguments
|
|
* (@src, @dst) must be aligned to 16 bytes and @len must be a multiple
|
|
* of 16.
|
|
*
|
|
* To test whether accelerated reads from WC are supported, use
|
|
* i915_memcpy_from_wc(NULL, NULL, 0);
|
|
*
|
|
* Returns true if the copy was successful, false if the preconditions
|
|
* are not met.
|
|
*/
|
|
bool i915_memcpy_from_wc(void *dst, const void *src, unsigned long len)
|
|
{
|
|
if (unlikely(((unsigned long)dst | (unsigned long)src | len) & 15))
|
|
return false;
|
|
|
|
#ifdef CONFIG_AS_MOVNTDQA
|
|
if (static_branch_likely(&has_movntdqa)) {
|
|
if (likely(len))
|
|
__memcpy_ntdqa(dst, src, len);
|
|
return true;
|
|
}
|
|
#endif
|
|
|
|
return false;
|
|
}
|
|
|
|
void i915_memcpy_init_early(struct drm_i915_private *dev_priv)
|
|
{
|
|
/*
|
|
* Some hypervisors (e.g. KVM) don't support VEX-prefix instructions
|
|
* emulation. So don't enable movntdqa in hypervisor guest.
|
|
*/
|
|
if (static_cpu_has(X86_FEATURE_XMM4_1) &&
|
|
!boot_cpu_has(X86_FEATURE_HYPERVISOR))
|
|
static_branch_enable(&has_movntdqa);
|
|
}
|