| Message ID | 1431516714-25816-3-git-send-email-drjones@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 13/05/2015 13:31, Andrew Jones wrote: > Commit 1050dcda30529 introduced KVM_MEMSLOT_INCOHERENT to flag memory > regions that may have coherency issues due to mapping host system RAM > as non-cacheable. This was introduced as a KVM internal flag, but now > give KVM userspace access to it so that it may use it for hinting > likely problematic regions. Also rename to KVM_MEM_UNCACHED. > > Signed-off-by: Andrew Jones <drjones@redhat.com> > --- > Documentation/virtual/kvm/api.txt | 20 ++++++++++++++------ > arch/arm/include/uapi/asm/kvm.h | 1 + > arch/arm/kvm/arm.c | 1 + > arch/arm/kvm/mmu.c | 4 ++-- > arch/arm64/include/uapi/asm/kvm.h | 1 + > include/linux/kvm_host.h | 1 - > include/uapi/linux/kvm.h | 2 ++ > virt/kvm/kvm_main.c | 7 ++++++- > 8 files changed, 27 insertions(+), 10 deletions(-) > > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > index 9fa2bf8c3f6f1..04ffd9f5db5f2 100644 > --- a/Documentation/virtual/kvm/api.txt > +++ b/Documentation/virtual/kvm/api.txt > @@ -905,6 +905,7 @@ struct kvm_userspace_memory_region { > /* for kvm_memory_region::flags */ > #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) > #define KVM_MEM_READONLY (1UL << 1) > +#define KVM_MEM_UNCACHED (1UL << 2) > > This ioctl allows the user to create or modify a guest physical memory > slot. When changing an existing slot, it may be moved in the guest > @@ -920,12 +921,19 @@ It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr > be identical. This allows large pages in the guest to be backed by large > pages in the host. > > -The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and > -KVM_MEM_READONLY. The former can be set to instruct KVM to keep track of > -writes to memory within the slot. See KVM_GET_DIRTY_LOG ioctl to know how to > -use it. The latter can be set, if KVM_CAP_READONLY_MEM capability allows it, > -to make a new slot read-only. In this case, writes to this memory will be > -posted to userspace as KVM_EXIT_MMIO exits. > +The flags field supports the following flags. All flags may be used in > +combination. > + - KVM_MEM_LOG_DIRTY_PAGES: no capability required > + Set this to instruct KVM to keep track of writes to memory within > + the slot. (See the KVM_GET_DIRTY_LOG ioctl) > + - KVM_MEM_READONLY: depends on capability KVM_CAP_READONLY_MEM > + Set this to make a new slot read-only. In this case, writes to > + this memory will be posted to userspace as KVM_EXIT_MMIO exits. > + EINVAL will be returned if the slot is not new. > + - KVM_MEM_UNCACHED: depends on capability KVM_CAP_UNCACHED_MEM > + Set this to make a new slot uncached, i.e. userspace will always > + directly read/write RAM for this memory region. EINVAL will be > + returned if the slot is not new. > > When the KVM_CAP_SYNC_MMU capability is available, changes in the backing of > the memory region are automatically reflected into the guest. For example, an > diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h > index df3f60cb1168a..893a331655115 100644 > --- a/arch/arm/include/uapi/asm/kvm.h > +++ b/arch/arm/include/uapi/asm/kvm.h > @@ -26,6 +26,7 @@ > #define __KVM_HAVE_GUEST_DEBUG > #define __KVM_HAVE_IRQ_LINE > #define __KVM_HAVE_READONLY_MEM > +#define __KVM_HAVE_UNCACHED_MEM > > #define KVM_REG_SIZE(id) \ > (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT)) > diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c > index d9631ecddd56e..cbb532de9c8b5 100644 > --- a/arch/arm/kvm/arm.c > +++ b/arch/arm/kvm/arm.c > @@ -182,6 +182,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) > case KVM_CAP_ARM_PSCI_0_2: > case KVM_CAP_READONLY_MEM: > case KVM_CAP_MP_STATE: > + case KVM_CAP_UNCACHED_MEM: > r = 1; > break; > case KVM_CAP_COALESCED_MMIO: > diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c > index 1d5accbd3dcf2..bc1665acd73e7 100644 > --- a/arch/arm/kvm/mmu.c > +++ b/arch/arm/kvm/mmu.c > @@ -1307,7 +1307,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, > if (!hugetlb && !force_pte) > hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa); > > - fault_ipa_uncached = memslot->flags & KVM_MEMSLOT_INCOHERENT; > + fault_ipa_uncached = memslot->flags & KVM_MEM_UNCACHED; > > if (hugetlb) { > pmd_t new_pmd = pfn_pmd(pfn, mem_type); > @@ -1834,7 +1834,7 @@ int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, > * regions as incoherent. > */ > if (slot->flags & KVM_MEM_READONLY) > - slot->flags |= KVM_MEMSLOT_INCOHERENT; > + slot->flags |= KVM_MEM_UNCACHED; > return 0; > } > > diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h > index d26832022127e..be46855ca01b7 100644 > --- a/arch/arm64/include/uapi/asm/kvm.h > +++ b/arch/arm64/include/uapi/asm/kvm.h > @@ -38,6 +38,7 @@ > #define __KVM_HAVE_GUEST_DEBUG > #define __KVM_HAVE_IRQ_LINE > #define __KVM_HAVE_READONLY_MEM > +#define __KVM_HAVE_UNCACHED_MEM > > #define KVM_REG_SIZE(id) \ > (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT)) > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h > index ad45054309a0f..74d6a14529f53 100644 > --- a/include/linux/kvm_host.h > +++ b/include/linux/kvm_host.h > @@ -39,7 +39,6 @@ > * include/linux/kvm_h. > */ > #define KVM_MEMSLOT_INVALID (1UL << 16) > -#define KVM_MEMSLOT_INCOHERENT (1UL << 17) > > /* Two fragments for cross MMIO pages. */ > #define KVM_MAX_MMIO_FRAGMENTS 2 > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 4b60056776d14..ceb6e805e5f77 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -108,6 +108,7 @@ struct kvm_userspace_memory_region { > */ > #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) > #define KVM_MEM_READONLY (1UL << 1) > +#define KVM_MEM_UNCACHED (1UL << 2) > > /* for KVM_IRQ_LINE */ > struct kvm_irq_level { > @@ -814,6 +815,7 @@ struct kvm_ppc_smmu_info { > #define KVM_CAP_S390_INJECT_IRQ 113 > #define KVM_CAP_S390_IRQ_STATE 114 > #define KVM_CAP_PPC_HWRNG 115 > +#define KVM_CAP_UNCACHED_MEM 116 > > #ifdef KVM_CAP_IRQ_ROUTING > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 90977418aeb6e..d1d535d80a075 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -719,6 +719,10 @@ static int check_memory_region_flags(struct kvm_userspace_memory_region *mem) > valid_flags |= KVM_MEM_READONLY; > #endif > > +#ifdef __KVM_HAVE_UNCACHED_MEM > + valid_flags |= KVM_MEM_UNCACHED; > +#endif > + > if (mem->flags & ~valid_flags) > return -EINVAL; > > @@ -816,7 +820,8 @@ int __kvm_set_memory_region(struct kvm *kvm, > else { /* Modify an existing slot. */ > if ((mem->userspace_addr != old.userspace_addr) || > (npages != old.npages) || > - ((new.flags ^ old.flags) & KVM_MEM_READONLY)) > + ((new.flags ^ old.flags) & > + (KVM_MEM_READONLY | KVM_MEM_UNCACHED))) > goto out; > > if (base_gfn != old.base_gfn) > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
On Wed, May 13, 2015 at 01:31:53PM +0200, Andrew Jones wrote: > Commit 1050dcda30529 introduced KVM_MEMSLOT_INCOHERENT to flag memory > regions that may have coherency issues due to mapping host system RAM > as non-cacheable. This was introduced as a KVM internal flag, but now > give KVM userspace access to it so that it may use it for hinting > likely problematic regions. Also rename to KVM_MEM_UNCACHED. > > Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 9fa2bf8c3f6f1..04ffd9f5db5f2 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -905,6 +905,7 @@ struct kvm_userspace_memory_region { /* for kvm_memory_region::flags */ #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) #define KVM_MEM_READONLY (1UL << 1) +#define KVM_MEM_UNCACHED (1UL << 2) This ioctl allows the user to create or modify a guest physical memory slot. When changing an existing slot, it may be moved in the guest @@ -920,12 +921,19 @@ It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr be identical. This allows large pages in the guest to be backed by large pages in the host. -The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and -KVM_MEM_READONLY. The former can be set to instruct KVM to keep track of -writes to memory within the slot. See KVM_GET_DIRTY_LOG ioctl to know how to -use it. The latter can be set, if KVM_CAP_READONLY_MEM capability allows it, -to make a new slot read-only. In this case, writes to this memory will be -posted to userspace as KVM_EXIT_MMIO exits. +The flags field supports the following flags. All flags may be used in +combination. + - KVM_MEM_LOG_DIRTY_PAGES: no capability required + Set this to instruct KVM to keep track of writes to memory within + the slot. (See the KVM_GET_DIRTY_LOG ioctl) + - KVM_MEM_READONLY: depends on capability KVM_CAP_READONLY_MEM + Set this to make a new slot read-only. In this case, writes to + this memory will be posted to userspace as KVM_EXIT_MMIO exits. + EINVAL will be returned if the slot is not new. + - KVM_MEM_UNCACHED: depends on capability KVM_CAP_UNCACHED_MEM + Set this to make a new slot uncached, i.e. userspace will always + directly read/write RAM for this memory region. EINVAL will be + returned if the slot is not new. When the KVM_CAP_SYNC_MMU capability is available, changes in the backing of the memory region are automatically reflected into the guest. For example, an diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index df3f60cb1168a..893a331655115 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -26,6 +26,7 @@ #define __KVM_HAVE_GUEST_DEBUG #define __KVM_HAVE_IRQ_LINE #define __KVM_HAVE_READONLY_MEM +#define __KVM_HAVE_UNCACHED_MEM #define KVM_REG_SIZE(id) \ (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT)) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index d9631ecddd56e..cbb532de9c8b5 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -182,6 +182,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_ARM_PSCI_0_2: case KVM_CAP_READONLY_MEM: case KVM_CAP_MP_STATE: + case KVM_CAP_UNCACHED_MEM: r = 1; break; case KVM_CAP_COALESCED_MMIO: diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 1d5accbd3dcf2..bc1665acd73e7 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -1307,7 +1307,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (!hugetlb && !force_pte) hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa); - fault_ipa_uncached = memslot->flags & KVM_MEMSLOT_INCOHERENT; + fault_ipa_uncached = memslot->flags & KVM_MEM_UNCACHED; if (hugetlb) { pmd_t new_pmd = pfn_pmd(pfn, mem_type); @@ -1834,7 +1834,7 @@ int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, * regions as incoherent. */ if (slot->flags & KVM_MEM_READONLY) - slot->flags |= KVM_MEMSLOT_INCOHERENT; + slot->flags |= KVM_MEM_UNCACHED; return 0; } diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index d26832022127e..be46855ca01b7 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -38,6 +38,7 @@ #define __KVM_HAVE_GUEST_DEBUG #define __KVM_HAVE_IRQ_LINE #define __KVM_HAVE_READONLY_MEM +#define __KVM_HAVE_UNCACHED_MEM #define KVM_REG_SIZE(id) \ (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT)) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index ad45054309a0f..74d6a14529f53 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -39,7 +39,6 @@ * include/linux/kvm_h. */ #define KVM_MEMSLOT_INVALID (1UL << 16) -#define KVM_MEMSLOT_INCOHERENT (1UL << 17) /* Two fragments for cross MMIO pages. */ #define KVM_MAX_MMIO_FRAGMENTS 2 diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 4b60056776d14..ceb6e805e5f77 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -108,6 +108,7 @@ struct kvm_userspace_memory_region { */ #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) #define KVM_MEM_READONLY (1UL << 1) +#define KVM_MEM_UNCACHED (1UL << 2) /* for KVM_IRQ_LINE */ struct kvm_irq_level { @@ -814,6 +815,7 @@ struct kvm_ppc_smmu_info { #define KVM_CAP_S390_INJECT_IRQ 113 #define KVM_CAP_S390_IRQ_STATE 114 #define KVM_CAP_PPC_HWRNG 115 +#define KVM_CAP_UNCACHED_MEM 116 #ifdef KVM_CAP_IRQ_ROUTING diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 90977418aeb6e..d1d535d80a075 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -719,6 +719,10 @@ static int check_memory_region_flags(struct kvm_userspace_memory_region *mem) valid_flags |= KVM_MEM_READONLY; #endif +#ifdef __KVM_HAVE_UNCACHED_MEM + valid_flags |= KVM_MEM_UNCACHED; +#endif + if (mem->flags & ~valid_flags) return -EINVAL; @@ -816,7 +820,8 @@ int __kvm_set_memory_region(struct kvm *kvm, else { /* Modify an existing slot. */ if ((mem->userspace_addr != old.userspace_addr) || (npages != old.npages) || - ((new.flags ^ old.flags) & KVM_MEM_READONLY)) + ((new.flags ^ old.flags) & + (KVM_MEM_READONLY | KVM_MEM_UNCACHED))) goto out; if (base_gfn != old.base_gfn)
Commit 1050dcda30529 introduced KVM_MEMSLOT_INCOHERENT to flag memory regions that may have coherency issues due to mapping host system RAM as non-cacheable. This was introduced as a KVM internal flag, but now give KVM userspace access to it so that it may use it for hinting likely problematic regions. Also rename to KVM_MEM_UNCACHED. Signed-off-by: Andrew Jones <drjones@redhat.com> --- Documentation/virtual/kvm/api.txt | 20 ++++++++++++++------ arch/arm/include/uapi/asm/kvm.h | 1 + arch/arm/kvm/arm.c | 1 + arch/arm/kvm/mmu.c | 4 ++-- arch/arm64/include/uapi/asm/kvm.h | 1 + include/linux/kvm_host.h | 1 - include/uapi/linux/kvm.h | 2 ++ virt/kvm/kvm_main.c | 7 ++++++- 8 files changed, 27 insertions(+), 10 deletions(-)