April 2022 - Linux-stable-mirror

FAILED: patch "[PATCH] drm/fb-helper: Mark screen buffers in system memory with" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From cd9f7f7ac5932129fe81b4c7559cfcb226ec7c5c Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann <tzimmermann(a)suse.de> Date: Tue, 1 Feb 2022 12:53:05 +0100 Subject: [PATCH] drm/fb-helper: Mark screen buffers in system memory with FBINFO_VIRTFB Mark screen buffers in system memory with FBINFO_VIRTFB. Otherwise, fbdev deferred I/O marks mmap'ed areas of system memory with VM_IO. (There's an inverse relationship between the two flags.) For shadow buffers, also set the FBINFO_READS_FAST hint. v3: * change FB_ to FBINFO_ in commit description v2: * updated commit description (Daniel) * added Fixes tag Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Fixes: d536540f304c ("drm/fb-helper: Add generic fbdev emulation .fb_probe function") Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: dri-devel(a)lists.freedesktop.org Cc: <stable(a)vger.kernel.org> # v4.19+ Link: https://patchwork.freedesktop.org/patch/msgid/20220201115305.9333-1-tzimmer… diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 9727a59d35fd..805c5a666490 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -2340,6 +2340,7 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper, fbi->fbops = &drm_fbdev_fb_ops; fbi->screen_size = sizes->surface_height * fb->pitches[0]; fbi->fix.smem_len = fbi->screen_size; + fbi->flags = FBINFO_DEFAULT; drm_fb_helper_fill_info(fbi, fb_helper, sizes); @@ -2347,19 +2348,21 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper, fbi->screen_buffer = vzalloc(fbi->screen_size); if (!fbi->screen_buffer) return -ENOMEM; + fbi->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST; fbi->fbdefio = &drm_fbdev_defio; - fb_deferred_io_init(fbi); } else { /* buffer is mapped for HW framebuffer */ ret = drm_client_buffer_vmap(fb_helper->buffer, &map); if (ret) return ret; - if (map.is_iomem) + if (map.is_iomem) { fbi->screen_base = map.vaddr_iomem; - else + } else { fbi->screen_buffer = map.vaddr; + fbi->flags |= FBINFO_VIRTFB; + } /* * Shamelessly leak the physical address to user-space. As

2 years, 8 months

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FAILED: patch "[PATCH] drm/fb-helper: Mark screen buffers in system memory with" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From cd9f7f7ac5932129fe81b4c7559cfcb226ec7c5c Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann <tzimmermann(a)suse.de> Date: Tue, 1 Feb 2022 12:53:05 +0100 Subject: [PATCH] drm/fb-helper: Mark screen buffers in system memory with FBINFO_VIRTFB Mark screen buffers in system memory with FBINFO_VIRTFB. Otherwise, fbdev deferred I/O marks mmap'ed areas of system memory with VM_IO. (There's an inverse relationship between the two flags.) For shadow buffers, also set the FBINFO_READS_FAST hint. v3: * change FB_ to FBINFO_ in commit description v2: * updated commit description (Daniel) * added Fixes tag Signed-off-by: Thomas Zimmermann <tzimmermann(a)suse.de> Fixes: d536540f304c ("drm/fb-helper: Add generic fbdev emulation .fb_probe function") Reviewed-by: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: dri-devel(a)lists.freedesktop.org Cc: <stable(a)vger.kernel.org> # v4.19+ Link: https://patchwork.freedesktop.org/patch/msgid/20220201115305.9333-1-tzimmer… diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 9727a59d35fd..805c5a666490 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -2340,6 +2340,7 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper, fbi->fbops = &drm_fbdev_fb_ops; fbi->screen_size = sizes->surface_height * fb->pitches[0]; fbi->fix.smem_len = fbi->screen_size; + fbi->flags = FBINFO_DEFAULT; drm_fb_helper_fill_info(fbi, fb_helper, sizes); @@ -2347,19 +2348,21 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper, fbi->screen_buffer = vzalloc(fbi->screen_size); if (!fbi->screen_buffer) return -ENOMEM; + fbi->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST; fbi->fbdefio = &drm_fbdev_defio; - fb_deferred_io_init(fbi); } else { /* buffer is mapped for HW framebuffer */ ret = drm_client_buffer_vmap(fb_helper->buffer, &map); if (ret) return ret; - if (map.is_iomem) + if (map.is_iomem) { fbi->screen_base = map.vaddr_iomem; - else + } else { fbi->screen_buffer = map.vaddr; + fbi->flags |= FBINFO_VIRTFB; + } /* * Shamelessly leak the physical address to user-space. As

2 years, 8 months

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FAILED: patch "[PATCH] KVM: use __vcalloc for very large allocations" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 37b2a6510a48ca361ced679f92682b7b7d7d0330 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Tue, 8 Mar 2022 04:49:37 -0500 Subject: [PATCH] KVM: use __vcalloc for very large allocations Allocations whose size is related to the memslot size can be arbitrarily large. Do not use kvzalloc/kvcalloc, as those are limited to "not crazy" sizes that fit in 32 bits. Cc: stable(a)vger.kernel.org Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls") Reviewed-by: David Hildenbrand <david(a)redhat.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index e414ca44839f..be441403925b 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -251,7 +251,7 @@ int kvmppc_uvmem_slot_init(struct kvm *kvm, const struct kvm_memory_slot *slot) p = kzalloc(sizeof(*p), GFP_KERNEL); if (!p) return -ENOMEM; - p->pfns = vzalloc(array_size(slot->npages, sizeof(*p->pfns))); + p->pfns = vcalloc(slot->npages, sizeof(*p->pfns)); if (!p->pfns) { kfree(p); return -ENOMEM; diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c index 68eb1fb548b6..2e09d1b6249f 100644 --- a/arch/x86/kvm/mmu/page_track.c +++ b/arch/x86/kvm/mmu/page_track.c @@ -47,8 +47,8 @@ int kvm_page_track_create_memslot(struct kvm *kvm, continue; slot->arch.gfn_track[i] = - kvcalloc(npages, sizeof(*slot->arch.gfn_track[i]), - GFP_KERNEL_ACCOUNT); + __vcalloc(npages, sizeof(*slot->arch.gfn_track[i]), + GFP_KERNEL_ACCOUNT); if (!slot->arch.gfn_track[i]) goto track_free; } @@ -75,7 +75,8 @@ int kvm_page_track_write_tracking_alloc(struct kvm_memory_slot *slot) if (slot->arch.gfn_track[KVM_PAGE_TRACK_WRITE]) return 0; - gfn_track = kvcalloc(slot->npages, sizeof(*gfn_track), GFP_KERNEL_ACCOUNT); + gfn_track = __vcalloc(slot->npages, sizeof(*gfn_track), + GFP_KERNEL_ACCOUNT); if (gfn_track == NULL) return -ENOMEM; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f79bf4552082..4fa4d8269e5b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11838,7 +11838,7 @@ int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages) if (slot->arch.rmap[i]) continue; - slot->arch.rmap[i] = kvcalloc(lpages, sz, GFP_KERNEL_ACCOUNT); + slot->arch.rmap[i] = __vcalloc(lpages, sz, GFP_KERNEL_ACCOUNT); if (!slot->arch.rmap[i]) { memslot_rmap_free(slot); return -ENOMEM; @@ -11875,7 +11875,7 @@ static int kvm_alloc_memslot_metadata(struct kvm *kvm, lpages = __kvm_mmu_slot_lpages(slot, npages, level); - linfo = kvcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT); + linfo = __vcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT); if (!linfo) goto out_free; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index c941b97fa133..69c318fdff61 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1274,9 +1274,9 @@ static int kvm_vm_release(struct inode *inode, struct file *filp) */ static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot) { - unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot); + unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(memslot); - memslot->dirty_bitmap = kvzalloc(dirty_bytes, GFP_KERNEL_ACCOUNT); + memslot->dirty_bitmap = __vcalloc(2, dirty_bytes, GFP_KERNEL_ACCOUNT); if (!memslot->dirty_bitmap) return -ENOMEM;

2 years, 8 months

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FAILED: patch "[PATCH] KVM: use __vcalloc for very large allocations" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 37b2a6510a48ca361ced679f92682b7b7d7d0330 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Tue, 8 Mar 2022 04:49:37 -0500 Subject: [PATCH] KVM: use __vcalloc for very large allocations Allocations whose size is related to the memslot size can be arbitrarily large. Do not use kvzalloc/kvcalloc, as those are limited to "not crazy" sizes that fit in 32 bits. Cc: stable(a)vger.kernel.org Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls") Reviewed-by: David Hildenbrand <david(a)redhat.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index e414ca44839f..be441403925b 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -251,7 +251,7 @@ int kvmppc_uvmem_slot_init(struct kvm *kvm, const struct kvm_memory_slot *slot) p = kzalloc(sizeof(*p), GFP_KERNEL); if (!p) return -ENOMEM; - p->pfns = vzalloc(array_size(slot->npages, sizeof(*p->pfns))); + p->pfns = vcalloc(slot->npages, sizeof(*p->pfns)); if (!p->pfns) { kfree(p); return -ENOMEM; diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c index 68eb1fb548b6..2e09d1b6249f 100644 --- a/arch/x86/kvm/mmu/page_track.c +++ b/arch/x86/kvm/mmu/page_track.c @@ -47,8 +47,8 @@ int kvm_page_track_create_memslot(struct kvm *kvm, continue; slot->arch.gfn_track[i] = - kvcalloc(npages, sizeof(*slot->arch.gfn_track[i]), - GFP_KERNEL_ACCOUNT); + __vcalloc(npages, sizeof(*slot->arch.gfn_track[i]), + GFP_KERNEL_ACCOUNT); if (!slot->arch.gfn_track[i]) goto track_free; } @@ -75,7 +75,8 @@ int kvm_page_track_write_tracking_alloc(struct kvm_memory_slot *slot) if (slot->arch.gfn_track[KVM_PAGE_TRACK_WRITE]) return 0; - gfn_track = kvcalloc(slot->npages, sizeof(*gfn_track), GFP_KERNEL_ACCOUNT); + gfn_track = __vcalloc(slot->npages, sizeof(*gfn_track), + GFP_KERNEL_ACCOUNT); if (gfn_track == NULL) return -ENOMEM; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f79bf4552082..4fa4d8269e5b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11838,7 +11838,7 @@ int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages) if (slot->arch.rmap[i]) continue; - slot->arch.rmap[i] = kvcalloc(lpages, sz, GFP_KERNEL_ACCOUNT); + slot->arch.rmap[i] = __vcalloc(lpages, sz, GFP_KERNEL_ACCOUNT); if (!slot->arch.rmap[i]) { memslot_rmap_free(slot); return -ENOMEM; @@ -11875,7 +11875,7 @@ static int kvm_alloc_memslot_metadata(struct kvm *kvm, lpages = __kvm_mmu_slot_lpages(slot, npages, level); - linfo = kvcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT); + linfo = __vcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT); if (!linfo) goto out_free; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index c941b97fa133..69c318fdff61 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1274,9 +1274,9 @@ static int kvm_vm_release(struct inode *inode, struct file *filp) */ static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot) { - unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot); + unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(memslot); - memslot->dirty_bitmap = kvzalloc(dirty_bytes, GFP_KERNEL_ACCOUNT); + memslot->dirty_bitmap = __vcalloc(2, dirty_bytes, GFP_KERNEL_ACCOUNT); if (!memslot->dirty_bitmap) return -ENOMEM;

2 years, 8 months

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FAILED: patch "[PATCH] KVM: use __vcalloc for very large allocations" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 37b2a6510a48ca361ced679f92682b7b7d7d0330 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Tue, 8 Mar 2022 04:49:37 -0500 Subject: [PATCH] KVM: use __vcalloc for very large allocations Allocations whose size is related to the memslot size can be arbitrarily large. Do not use kvzalloc/kvcalloc, as those are limited to "not crazy" sizes that fit in 32 bits. Cc: stable(a)vger.kernel.org Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls") Reviewed-by: David Hildenbrand <david(a)redhat.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index e414ca44839f..be441403925b 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -251,7 +251,7 @@ int kvmppc_uvmem_slot_init(struct kvm *kvm, const struct kvm_memory_slot *slot) p = kzalloc(sizeof(*p), GFP_KERNEL); if (!p) return -ENOMEM; - p->pfns = vzalloc(array_size(slot->npages, sizeof(*p->pfns))); + p->pfns = vcalloc(slot->npages, sizeof(*p->pfns)); if (!p->pfns) { kfree(p); return -ENOMEM; diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c index 68eb1fb548b6..2e09d1b6249f 100644 --- a/arch/x86/kvm/mmu/page_track.c +++ b/arch/x86/kvm/mmu/page_track.c @@ -47,8 +47,8 @@ int kvm_page_track_create_memslot(struct kvm *kvm, continue; slot->arch.gfn_track[i] = - kvcalloc(npages, sizeof(*slot->arch.gfn_track[i]), - GFP_KERNEL_ACCOUNT); + __vcalloc(npages, sizeof(*slot->arch.gfn_track[i]), + GFP_KERNEL_ACCOUNT); if (!slot->arch.gfn_track[i]) goto track_free; } @@ -75,7 +75,8 @@ int kvm_page_track_write_tracking_alloc(struct kvm_memory_slot *slot) if (slot->arch.gfn_track[KVM_PAGE_TRACK_WRITE]) return 0; - gfn_track = kvcalloc(slot->npages, sizeof(*gfn_track), GFP_KERNEL_ACCOUNT); + gfn_track = __vcalloc(slot->npages, sizeof(*gfn_track), + GFP_KERNEL_ACCOUNT); if (gfn_track == NULL) return -ENOMEM; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f79bf4552082..4fa4d8269e5b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11838,7 +11838,7 @@ int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages) if (slot->arch.rmap[i]) continue; - slot->arch.rmap[i] = kvcalloc(lpages, sz, GFP_KERNEL_ACCOUNT); + slot->arch.rmap[i] = __vcalloc(lpages, sz, GFP_KERNEL_ACCOUNT); if (!slot->arch.rmap[i]) { memslot_rmap_free(slot); return -ENOMEM; @@ -11875,7 +11875,7 @@ static int kvm_alloc_memslot_metadata(struct kvm *kvm, lpages = __kvm_mmu_slot_lpages(slot, npages, level); - linfo = kvcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT); + linfo = __vcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT); if (!linfo) goto out_free; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index c941b97fa133..69c318fdff61 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1274,9 +1274,9 @@ static int kvm_vm_release(struct inode *inode, struct file *filp) */ static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot) { - unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot); + unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(memslot); - memslot->dirty_bitmap = kvzalloc(dirty_bytes, GFP_KERNEL_ACCOUNT); + memslot->dirty_bitmap = __vcalloc(2, dirty_bytes, GFP_KERNEL_ACCOUNT); if (!memslot->dirty_bitmap) return -ENOMEM;

2 years, 8 months

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FAILED: patch "[PATCH] KVM: use __vcalloc for very large allocations" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 37b2a6510a48ca361ced679f92682b7b7d7d0330 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Tue, 8 Mar 2022 04:49:37 -0500 Subject: [PATCH] KVM: use __vcalloc for very large allocations Allocations whose size is related to the memslot size can be arbitrarily large. Do not use kvzalloc/kvcalloc, as those are limited to "not crazy" sizes that fit in 32 bits. Cc: stable(a)vger.kernel.org Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls") Reviewed-by: David Hildenbrand <david(a)redhat.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index e414ca44839f..be441403925b 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -251,7 +251,7 @@ int kvmppc_uvmem_slot_init(struct kvm *kvm, const struct kvm_memory_slot *slot) p = kzalloc(sizeof(*p), GFP_KERNEL); if (!p) return -ENOMEM; - p->pfns = vzalloc(array_size(slot->npages, sizeof(*p->pfns))); + p->pfns = vcalloc(slot->npages, sizeof(*p->pfns)); if (!p->pfns) { kfree(p); return -ENOMEM; diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c index 68eb1fb548b6..2e09d1b6249f 100644 --- a/arch/x86/kvm/mmu/page_track.c +++ b/arch/x86/kvm/mmu/page_track.c @@ -47,8 +47,8 @@ int kvm_page_track_create_memslot(struct kvm *kvm, continue; slot->arch.gfn_track[i] = - kvcalloc(npages, sizeof(*slot->arch.gfn_track[i]), - GFP_KERNEL_ACCOUNT); + __vcalloc(npages, sizeof(*slot->arch.gfn_track[i]), + GFP_KERNEL_ACCOUNT); if (!slot->arch.gfn_track[i]) goto track_free; } @@ -75,7 +75,8 @@ int kvm_page_track_write_tracking_alloc(struct kvm_memory_slot *slot) if (slot->arch.gfn_track[KVM_PAGE_TRACK_WRITE]) return 0; - gfn_track = kvcalloc(slot->npages, sizeof(*gfn_track), GFP_KERNEL_ACCOUNT); + gfn_track = __vcalloc(slot->npages, sizeof(*gfn_track), + GFP_KERNEL_ACCOUNT); if (gfn_track == NULL) return -ENOMEM; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f79bf4552082..4fa4d8269e5b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11838,7 +11838,7 @@ int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages) if (slot->arch.rmap[i]) continue; - slot->arch.rmap[i] = kvcalloc(lpages, sz, GFP_KERNEL_ACCOUNT); + slot->arch.rmap[i] = __vcalloc(lpages, sz, GFP_KERNEL_ACCOUNT); if (!slot->arch.rmap[i]) { memslot_rmap_free(slot); return -ENOMEM; @@ -11875,7 +11875,7 @@ static int kvm_alloc_memslot_metadata(struct kvm *kvm, lpages = __kvm_mmu_slot_lpages(slot, npages, level); - linfo = kvcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT); + linfo = __vcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT); if (!linfo) goto out_free; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index c941b97fa133..69c318fdff61 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1274,9 +1274,9 @@ static int kvm_vm_release(struct inode *inode, struct file *filp) */ static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot) { - unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot); + unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(memslot); - memslot->dirty_bitmap = kvzalloc(dirty_bytes, GFP_KERNEL_ACCOUNT); + memslot->dirty_bitmap = __vcalloc(2, dirty_bytes, GFP_KERNEL_ACCOUNT); if (!memslot->dirty_bitmap) return -ENOMEM;

2 years, 8 months

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FAILED: patch "[PATCH] KVM: use __vcalloc for very large allocations" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 37b2a6510a48ca361ced679f92682b7b7d7d0330 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Tue, 8 Mar 2022 04:49:37 -0500 Subject: [PATCH] KVM: use __vcalloc for very large allocations Allocations whose size is related to the memslot size can be arbitrarily large. Do not use kvzalloc/kvcalloc, as those are limited to "not crazy" sizes that fit in 32 bits. Cc: stable(a)vger.kernel.org Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls") Reviewed-by: David Hildenbrand <david(a)redhat.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index e414ca44839f..be441403925b 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -251,7 +251,7 @@ int kvmppc_uvmem_slot_init(struct kvm *kvm, const struct kvm_memory_slot *slot) p = kzalloc(sizeof(*p), GFP_KERNEL); if (!p) return -ENOMEM; - p->pfns = vzalloc(array_size(slot->npages, sizeof(*p->pfns))); + p->pfns = vcalloc(slot->npages, sizeof(*p->pfns)); if (!p->pfns) { kfree(p); return -ENOMEM; diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c index 68eb1fb548b6..2e09d1b6249f 100644 --- a/arch/x86/kvm/mmu/page_track.c +++ b/arch/x86/kvm/mmu/page_track.c @@ -47,8 +47,8 @@ int kvm_page_track_create_memslot(struct kvm *kvm, continue; slot->arch.gfn_track[i] = - kvcalloc(npages, sizeof(*slot->arch.gfn_track[i]), - GFP_KERNEL_ACCOUNT); + __vcalloc(npages, sizeof(*slot->arch.gfn_track[i]), + GFP_KERNEL_ACCOUNT); if (!slot->arch.gfn_track[i]) goto track_free; } @@ -75,7 +75,8 @@ int kvm_page_track_write_tracking_alloc(struct kvm_memory_slot *slot) if (slot->arch.gfn_track[KVM_PAGE_TRACK_WRITE]) return 0; - gfn_track = kvcalloc(slot->npages, sizeof(*gfn_track), GFP_KERNEL_ACCOUNT); + gfn_track = __vcalloc(slot->npages, sizeof(*gfn_track), + GFP_KERNEL_ACCOUNT); if (gfn_track == NULL) return -ENOMEM; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f79bf4552082..4fa4d8269e5b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11838,7 +11838,7 @@ int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages) if (slot->arch.rmap[i]) continue; - slot->arch.rmap[i] = kvcalloc(lpages, sz, GFP_KERNEL_ACCOUNT); + slot->arch.rmap[i] = __vcalloc(lpages, sz, GFP_KERNEL_ACCOUNT); if (!slot->arch.rmap[i]) { memslot_rmap_free(slot); return -ENOMEM; @@ -11875,7 +11875,7 @@ static int kvm_alloc_memslot_metadata(struct kvm *kvm, lpages = __kvm_mmu_slot_lpages(slot, npages, level); - linfo = kvcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT); + linfo = __vcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT); if (!linfo) goto out_free; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index c941b97fa133..69c318fdff61 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1274,9 +1274,9 @@ static int kvm_vm_release(struct inode *inode, struct file *filp) */ static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot) { - unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot); + unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(memslot); - memslot->dirty_bitmap = kvzalloc(dirty_bytes, GFP_KERNEL_ACCOUNT); + memslot->dirty_bitmap = __vcalloc(2, dirty_bytes, GFP_KERNEL_ACCOUNT); if (!memslot->dirty_bitmap) return -ENOMEM;

2 years, 8 months

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FAILED: patch "[PATCH] KVM: use __vcalloc for very large allocations" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 37b2a6510a48ca361ced679f92682b7b7d7d0330 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Tue, 8 Mar 2022 04:49:37 -0500 Subject: [PATCH] KVM: use __vcalloc for very large allocations Allocations whose size is related to the memslot size can be arbitrarily large. Do not use kvzalloc/kvcalloc, as those are limited to "not crazy" sizes that fit in 32 bits. Cc: stable(a)vger.kernel.org Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls") Reviewed-by: David Hildenbrand <david(a)redhat.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index e414ca44839f..be441403925b 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -251,7 +251,7 @@ int kvmppc_uvmem_slot_init(struct kvm *kvm, const struct kvm_memory_slot *slot) p = kzalloc(sizeof(*p), GFP_KERNEL); if (!p) return -ENOMEM; - p->pfns = vzalloc(array_size(slot->npages, sizeof(*p->pfns))); + p->pfns = vcalloc(slot->npages, sizeof(*p->pfns)); if (!p->pfns) { kfree(p); return -ENOMEM; diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c index 68eb1fb548b6..2e09d1b6249f 100644 --- a/arch/x86/kvm/mmu/page_track.c +++ b/arch/x86/kvm/mmu/page_track.c @@ -47,8 +47,8 @@ int kvm_page_track_create_memslot(struct kvm *kvm, continue; slot->arch.gfn_track[i] = - kvcalloc(npages, sizeof(*slot->arch.gfn_track[i]), - GFP_KERNEL_ACCOUNT); + __vcalloc(npages, sizeof(*slot->arch.gfn_track[i]), + GFP_KERNEL_ACCOUNT); if (!slot->arch.gfn_track[i]) goto track_free; } @@ -75,7 +75,8 @@ int kvm_page_track_write_tracking_alloc(struct kvm_memory_slot *slot) if (slot->arch.gfn_track[KVM_PAGE_TRACK_WRITE]) return 0; - gfn_track = kvcalloc(slot->npages, sizeof(*gfn_track), GFP_KERNEL_ACCOUNT); + gfn_track = __vcalloc(slot->npages, sizeof(*gfn_track), + GFP_KERNEL_ACCOUNT); if (gfn_track == NULL) return -ENOMEM; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f79bf4552082..4fa4d8269e5b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11838,7 +11838,7 @@ int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages) if (slot->arch.rmap[i]) continue; - slot->arch.rmap[i] = kvcalloc(lpages, sz, GFP_KERNEL_ACCOUNT); + slot->arch.rmap[i] = __vcalloc(lpages, sz, GFP_KERNEL_ACCOUNT); if (!slot->arch.rmap[i]) { memslot_rmap_free(slot); return -ENOMEM; @@ -11875,7 +11875,7 @@ static int kvm_alloc_memslot_metadata(struct kvm *kvm, lpages = __kvm_mmu_slot_lpages(slot, npages, level); - linfo = kvcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT); + linfo = __vcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT); if (!linfo) goto out_free; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index c941b97fa133..69c318fdff61 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1274,9 +1274,9 @@ static int kvm_vm_release(struct inode *inode, struct file *filp) */ static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot) { - unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot); + unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(memslot); - memslot->dirty_bitmap = kvzalloc(dirty_bytes, GFP_KERNEL_ACCOUNT); + memslot->dirty_bitmap = __vcalloc(2, dirty_bytes, GFP_KERNEL_ACCOUNT); if (!memslot->dirty_bitmap) return -ENOMEM;

2 years, 8 months

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FAILED: patch "[PATCH] KVM: s390x: fix SCK locking" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From c0573ba5c5a2244dc02060b1f374d4593c1d20b7 Mon Sep 17 00:00:00 2001 From: Claudio Imbrenda <imbrenda(a)linux.ibm.com> Date: Tue, 1 Mar 2022 15:33:40 +0100 Subject: [PATCH] KVM: s390x: fix SCK locking When handling the SCK instruction, the kvm lock is taken, even though the vcpu lock is already being held. The normal locking order is kvm lock first and then vcpu lock. This is can (and in some circumstances does) lead to deadlocks. The function kvm_s390_set_tod_clock is called both by the SCK handler and by some IOCTLs to set the clock. The IOCTLs will not hold the vcpu lock, so they can safely take the kvm lock. The SCK handler holds the vcpu lock, but will also somehow need to acquire the kvm lock without relinquishing the vcpu lock. The solution is to factor out the code to set the clock, and provide two wrappers. One is called like the original function and does the locking, the other is called kvm_s390_try_set_tod_clock and uses trylock to try to acquire the kvm lock. This new wrapper is then used in the SCK handler. If locking fails, -EAGAIN is returned, which is eventually propagated to userspace, thus also freeing the vcpu lock and allowing for forward progress. This is not the most efficient or elegant way to solve this issue, but the SCK instruction is deprecated and its performance is not critical. The goal of this patch is just to provide a simple but correct way to fix the bug. Fixes: 6a3f95a6b04c ("KVM: s390: Intercept SCK instruction") Signed-off-by: Claudio Imbrenda <imbrenda(a)linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger(a)linux.ibm.com> Reviewed-by: Janis Schoetterl-Glausch <scgl(a)linux.ibm.com> Link: https://lore.kernel.org/r/20220301143340.111129-1-imbrenda@linux.ibm.com Cc: stable(a)vger.kernel.org Signed-off-by: Christian Borntraeger <borntraeger(a)linux.ibm.com> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index b5ea95cf8686..b53ff693b66e 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -3961,14 +3961,12 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu) return 0; } -void kvm_s390_set_tod_clock(struct kvm *kvm, - const struct kvm_s390_vm_tod_clock *gtod) +static void __kvm_s390_set_tod_clock(struct kvm *kvm, const struct kvm_s390_vm_tod_clock *gtod) { struct kvm_vcpu *vcpu; union tod_clock clk; unsigned long i; - mutex_lock(&kvm->lock); preempt_disable(); store_tod_clock_ext(&clk); @@ -3989,7 +3987,22 @@ void kvm_s390_set_tod_clock(struct kvm *kvm, kvm_s390_vcpu_unblock_all(kvm); preempt_enable(); +} + +void kvm_s390_set_tod_clock(struct kvm *kvm, const struct kvm_s390_vm_tod_clock *gtod) +{ + mutex_lock(&kvm->lock); + __kvm_s390_set_tod_clock(kvm, gtod); + mutex_unlock(&kvm->lock); +} + +int kvm_s390_try_set_tod_clock(struct kvm *kvm, const struct kvm_s390_vm_tod_clock *gtod) +{ + if (!mutex_trylock(&kvm->lock)) + return 0; + __kvm_s390_set_tod_clock(kvm, gtod); mutex_unlock(&kvm->lock); + return 1; } /** diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 4ba8fc30d87a..798955b62fa3 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -358,8 +358,8 @@ int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu); int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu); /* implemented in kvm-s390.c */ -void kvm_s390_set_tod_clock(struct kvm *kvm, - const struct kvm_s390_vm_tod_clock *gtod); +void kvm_s390_set_tod_clock(struct kvm *kvm, const struct kvm_s390_vm_tod_clock *gtod); +int kvm_s390_try_set_tod_clock(struct kvm *kvm, const struct kvm_s390_vm_tod_clock *gtod); long kvm_arch_fault_in_page(struct kvm_vcpu *vcpu, gpa_t gpa, int writable); int kvm_s390_store_status_unloaded(struct kvm_vcpu *vcpu, unsigned long addr); int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr); diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 30b24c42ef99..5beb7a4a11b3 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -102,7 +102,20 @@ static int handle_set_clock(struct kvm_vcpu *vcpu) return kvm_s390_inject_prog_cond(vcpu, rc); VCPU_EVENT(vcpu, 3, "SCK: setting guest TOD to 0x%llx", gtod.tod); - kvm_s390_set_tod_clock(vcpu->kvm, &gtod); + /* + * To set the TOD clock the kvm lock must be taken, but the vcpu lock + * is already held in handle_set_clock. The usual lock order is the + * opposite. As SCK is deprecated and should not be used in several + * cases, for example when the multiple epoch facility or TOD clock + * steering facility is installed (see Principles of Operation), a + * slow path can be used. If the lock can not be taken via try_lock, + * the instruction will be retried via -EAGAIN at a later point in + * time. + */ + if (!kvm_s390_try_set_tod_clock(vcpu->kvm, &gtod)) { + kvm_s390_retry_instr(vcpu); + return -EAGAIN; + } kvm_s390_set_psw_cc(vcpu, 0); return 0;

2 years, 8 months

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FAILED: patch "[PATCH] KVM: s390x: fix SCK locking" failed to apply to 5.16-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.16-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From c0573ba5c5a2244dc02060b1f374d4593c1d20b7 Mon Sep 17 00:00:00 2001 From: Claudio Imbrenda <imbrenda(a)linux.ibm.com> Date: Tue, 1 Mar 2022 15:33:40 +0100 Subject: [PATCH] KVM: s390x: fix SCK locking When handling the SCK instruction, the kvm lock is taken, even though the vcpu lock is already being held. The normal locking order is kvm lock first and then vcpu lock. This is can (and in some circumstances does) lead to deadlocks. The function kvm_s390_set_tod_clock is called both by the SCK handler and by some IOCTLs to set the clock. The IOCTLs will not hold the vcpu lock, so they can safely take the kvm lock. The SCK handler holds the vcpu lock, but will also somehow need to acquire the kvm lock without relinquishing the vcpu lock. The solution is to factor out the code to set the clock, and provide two wrappers. One is called like the original function and does the locking, the other is called kvm_s390_try_set_tod_clock and uses trylock to try to acquire the kvm lock. This new wrapper is then used in the SCK handler. If locking fails, -EAGAIN is returned, which is eventually propagated to userspace, thus also freeing the vcpu lock and allowing for forward progress. This is not the most efficient or elegant way to solve this issue, but the SCK instruction is deprecated and its performance is not critical. The goal of this patch is just to provide a simple but correct way to fix the bug. Fixes: 6a3f95a6b04c ("KVM: s390: Intercept SCK instruction") Signed-off-by: Claudio Imbrenda <imbrenda(a)linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger(a)linux.ibm.com> Reviewed-by: Janis Schoetterl-Glausch <scgl(a)linux.ibm.com> Link: https://lore.kernel.org/r/20220301143340.111129-1-imbrenda@linux.ibm.com Cc: stable(a)vger.kernel.org Signed-off-by: Christian Borntraeger <borntraeger(a)linux.ibm.com> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index b5ea95cf8686..b53ff693b66e 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -3961,14 +3961,12 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu) return 0; } -void kvm_s390_set_tod_clock(struct kvm *kvm, - const struct kvm_s390_vm_tod_clock *gtod) +static void __kvm_s390_set_tod_clock(struct kvm *kvm, const struct kvm_s390_vm_tod_clock *gtod) { struct kvm_vcpu *vcpu; union tod_clock clk; unsigned long i; - mutex_lock(&kvm->lock); preempt_disable(); store_tod_clock_ext(&clk); @@ -3989,7 +3987,22 @@ void kvm_s390_set_tod_clock(struct kvm *kvm, kvm_s390_vcpu_unblock_all(kvm); preempt_enable(); +} + +void kvm_s390_set_tod_clock(struct kvm *kvm, const struct kvm_s390_vm_tod_clock *gtod) +{ + mutex_lock(&kvm->lock); + __kvm_s390_set_tod_clock(kvm, gtod); + mutex_unlock(&kvm->lock); +} + +int kvm_s390_try_set_tod_clock(struct kvm *kvm, const struct kvm_s390_vm_tod_clock *gtod) +{ + if (!mutex_trylock(&kvm->lock)) + return 0; + __kvm_s390_set_tod_clock(kvm, gtod); mutex_unlock(&kvm->lock); + return 1; } /** diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 4ba8fc30d87a..798955b62fa3 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -358,8 +358,8 @@ int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu); int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu); /* implemented in kvm-s390.c */ -void kvm_s390_set_tod_clock(struct kvm *kvm, - const struct kvm_s390_vm_tod_clock *gtod); +void kvm_s390_set_tod_clock(struct kvm *kvm, const struct kvm_s390_vm_tod_clock *gtod); +int kvm_s390_try_set_tod_clock(struct kvm *kvm, const struct kvm_s390_vm_tod_clock *gtod); long kvm_arch_fault_in_page(struct kvm_vcpu *vcpu, gpa_t gpa, int writable); int kvm_s390_store_status_unloaded(struct kvm_vcpu *vcpu, unsigned long addr); int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr); diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 30b24c42ef99..5beb7a4a11b3 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -102,7 +102,20 @@ static int handle_set_clock(struct kvm_vcpu *vcpu) return kvm_s390_inject_prog_cond(vcpu, rc); VCPU_EVENT(vcpu, 3, "SCK: setting guest TOD to 0x%llx", gtod.tod); - kvm_s390_set_tod_clock(vcpu->kvm, &gtod); + /* + * To set the TOD clock the kvm lock must be taken, but the vcpu lock + * is already held in handle_set_clock. The usual lock order is the + * opposite. As SCK is deprecated and should not be used in several + * cases, for example when the multiple epoch facility or TOD clock + * steering facility is installed (see Principles of Operation), a + * slow path can be used. If the lock can not be taken via try_lock, + * the instruction will be retried via -EAGAIN at a later point in + * time. + */ + if (!kvm_s390_try_set_tod_clock(vcpu->kvm, &gtod)) { + kvm_s390_retry_instr(vcpu); + return -EAGAIN; + } kvm_s390_set_psw_cc(vcpu, 0); return 0;

2 years, 8 months

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