* [PATCH 1/2] mm: Add and export vmf_insert_mixed_prot()
2019-12-03 7:54 [PATCH 0/2] mm, drm/ttm: Fix pte insertion with customized protection Thomas Hellström (VMware)
@ 2019-12-03 7:54 ` Thomas Hellström (VMware)
2019-12-03 7:54 ` [PATCH 2/2] drm/ttm: Fix vm page protection handling Thomas Hellström (VMware)
1 sibling, 0 replies; 6+ messages in thread
From: Thomas Hellström (VMware) @ 2019-12-03 7:54 UTC (permalink / raw)
To: linux-mm, linux-kernel, dri-devel
Cc: pv-drivers, linux-graphics-maintainer, Thomas Hellstrom,
Andrew Morton, Michal Hocko, Matthew Wilcox (Oracle),
Kirill A. Shutemov, Ralph Campbell, Jérôme Glisse,
Christian König
From: Thomas Hellstrom <thellstrom@vmware.com>
The TTM module today uses a hack to be able to set a different page
protection than struct vm_area_struct::vm_page_prot. To be able to do
this properly, add and export vmf_insert_mixed_prot().
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: "Christian König" <christian.koenig@amd.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Acked-by: Christian König <christian.koenig@amd.com>
---
include/linux/mm.h | 2 ++
mm/memory.c | 15 +++++++++++----
2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index cc292273e6ba..29575d3c1e47 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2548,6 +2548,8 @@ vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn, pgprot_t pgprot);
vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
pfn_t pfn);
+vm_fault_t vmf_insert_mixed_prot(struct vm_area_struct *vma, unsigned long addr,
+ pfn_t pfn, pgprot_t pgprot);
vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
unsigned long addr, pfn_t pfn);
int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
diff --git a/mm/memory.c b/mm/memory.c
index b1ca51a079f2..28f162e28144 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1719,9 +1719,9 @@ static bool vm_mixed_ok(struct vm_area_struct *vma, pfn_t pfn)
}
static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
- unsigned long addr, pfn_t pfn, bool mkwrite)
+ unsigned long addr, pfn_t pfn, pgprot_t pgprot,
+ bool mkwrite)
{
- pgprot_t pgprot = vma->vm_page_prot;
int err;
BUG_ON(!vm_mixed_ok(vma, pfn));
@@ -1764,10 +1764,17 @@ static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
return VM_FAULT_NOPAGE;
}
+vm_fault_t vmf_insert_mixed_prot(struct vm_area_struct *vma, unsigned long addr,
+ pfn_t pfn, pgprot_t pgprot)
+{
+ return __vm_insert_mixed(vma, addr, pfn, pgprot, false);
+}
+EXPORT_SYMBOL(vmf_insert_mixed_prot);
+
vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
pfn_t pfn)
{
- return __vm_insert_mixed(vma, addr, pfn, false);
+ return __vm_insert_mixed(vma, addr, pfn, vma->vm_page_prot, false);
}
EXPORT_SYMBOL(vmf_insert_mixed);
@@ -1779,7 +1786,7 @@ EXPORT_SYMBOL(vmf_insert_mixed);
vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
unsigned long addr, pfn_t pfn)
{
- return __vm_insert_mixed(vma, addr, pfn, true);
+ return __vm_insert_mixed(vma, addr, pfn, vma->vm_page_prot, true);
}
EXPORT_SYMBOL(vmf_insert_mixed_mkwrite);
--
2.21.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/2] drm/ttm: Fix vm page protection handling
2019-12-03 7:54 [PATCH 0/2] mm, drm/ttm: Fix pte insertion with customized protection Thomas Hellström (VMware)
2019-12-03 7:54 ` [PATCH 1/2] mm: Add and export vmf_insert_mixed_prot() Thomas Hellström (VMware)
@ 2019-12-03 7:54 ` Thomas Hellström (VMware)
2019-12-03 9:55 ` Kirill A. Shutemov
1 sibling, 1 reply; 6+ messages in thread
From: Thomas Hellström (VMware) @ 2019-12-03 7:54 UTC (permalink / raw)
To: linux-mm, linux-kernel, dri-devel
Cc: pv-drivers, linux-graphics-maintainer, Thomas Hellstrom,
Andrew Morton, Michal Hocko, Matthew Wilcox (Oracle),
Kirill A. Shutemov, Ralph Campbell, Jérôme Glisse,
Christian König
From: Thomas Hellstrom <thellstrom@vmware.com>
We were using an ugly hack to set the page protection correctly.
Fix that and instead use vmf_insert_mixed_prot() and / or
vmf_insert_pfn_prot().
Also get the default page protection from
struct vm_area_struct::vm_page_prot rather than using vm_get_page_prot().
This way we catch modifications done by the vm system for drivers that
want write-notification.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: "Christian König" <christian.koenig@amd.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
---
drivers/gpu/drm/ttm/ttm_bo_vm.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index e6495ca2630b..2098f8d4dfc5 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -173,7 +173,6 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
pgoff_t num_prefault)
{
struct vm_area_struct *vma = vmf->vma;
- struct vm_area_struct cvma = *vma;
struct ttm_buffer_object *bo = vma->vm_private_data;
struct ttm_bo_device *bdev = bo->bdev;
unsigned long page_offset;
@@ -244,7 +243,7 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
goto out_io_unlock;
}
- cvma.vm_page_prot = ttm_io_prot(bo->mem.placement, prot);
+ prot = ttm_io_prot(bo->mem.placement, prot);
if (!bo->mem.bus.is_iomem) {
struct ttm_operation_ctx ctx = {
.interruptible = false,
@@ -260,7 +259,7 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
}
} else {
/* Iomem should not be marked encrypted */
- cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot);
+ prot = pgprot_decrypted(prot);
}
/*
@@ -284,10 +283,11 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
}
if (vma->vm_flags & VM_MIXEDMAP)
- ret = vmf_insert_mixed(&cvma, address,
- __pfn_to_pfn_t(pfn, PFN_DEV));
+ ret = vmf_insert_mixed_prot(vma, address,
+ __pfn_to_pfn_t(pfn, PFN_DEV),
+ prot);
else
- ret = vmf_insert_pfn(&cvma, address, pfn);
+ ret = vmf_insert_pfn_prot(vma, address, pfn, prot);
/* Never error on prefaulted PTEs */
if (unlikely((ret & VM_FAULT_ERROR))) {
@@ -319,7 +319,7 @@ vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
if (ret)
return ret;
- prot = vm_get_page_prot(vma->vm_flags);
+ prot = vma->vm_page_prot;
ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT);
if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
return ret;
--
2.21.0
^ permalink raw reply related [flat|nested] 6+ messages in thread