| Message ID | 20230608123448.71861-1-kconsul@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | KVM: ppc64: Enable ring-based dirty memory tracking | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | fail | sparse (ppc64le, ppc64le, fedora-37) failed at step Build. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | fail | kernel (ppc64le_guest_defconfig, fedora-37, ppc64le) failed at step Build. |
| snowpatch_ozlabs/github-powerpc_clang | fail | 2 of 6 jobs failed. |
Hi Nick/Gavin/Everyone, On 2023-06-08 08:34:48, Kautuk Consul wrote: > - Enable CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL as ppc64 is weakly > ordered. > - Enable CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP because the > kvmppc_xive_native_set_attr is called in the context of an ioctl > syscall and will call kvmppc_xive_native_eq_sync for setting the > KVM_DEV_XIVE_EQ_SYNC attribute which will call mark_dirty_page() > when there isn't a running vcpu. Implemented the > kvm_arch_allow_write_without_running_vcpu to always return true > to allow mark_page_dirty_in_slot to mark the page dirty in the > memslot->dirty_bitmap in this case. > - Set KVM_DIRTY_LOG_PAGE_OFFSET for the ring buffer's physical page > offset. > - Implement the kvm_arch_mmu_enable_log_dirty_pt_masked function required > for the generic KVM code to call. > - Add a check to kvmppc_vcpu_run_hv for checking whether the dirty > ring is soft full. > - Implement the kvm_arch_flush_remote_tlbs_memslot function to support > the CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT config option. > > On testing with live migration it was found that there is around > 150-180 ms improvment in overall migration time with this patch. > > Signed-off-by: Kautuk Consul <kconsul@linux.vnet.ibm.com> > --- > Documentation/virt/kvm/api.rst | 2 +- > arch/powerpc/include/uapi/asm/kvm.h | 2 ++ > arch/powerpc/kvm/Kconfig | 2 ++ > arch/powerpc/kvm/book3s_64_mmu_hv.c | 42 +++++++++++++++++++++++++++++ > arch/powerpc/kvm/book3s_hv.c | 3 +++ > include/linux/kvm_dirty_ring.h | 5 ++++ > 6 files changed, 55 insertions(+), 1 deletion(-) > Any review comments on this ? > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > index add067793b90..ce1ebc513bae 100644 > --- a/Documentation/virt/kvm/api.rst > +++ b/Documentation/virt/kvm/api.rst > @@ -8114,7 +8114,7 @@ regardless of what has actually been exposed through the CPUID leaf. > 8.29 KVM_CAP_DIRTY_LOG_RING/KVM_CAP_DIRTY_LOG_RING_ACQ_REL > ---------------------------------------------------------- > > -:Architectures: x86, arm64 > +:Architectures: x86, arm64, ppc64 > :Parameters: args[0] - size of the dirty log ring > > KVM is capable of tracking dirty memory using ring buffers that are > diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h > index 9f18fa090f1f..f722309ed7fb 100644 > --- a/arch/powerpc/include/uapi/asm/kvm.h > +++ b/arch/powerpc/include/uapi/asm/kvm.h > @@ -33,6 +33,8 @@ > /* Not always available, but if it is, this is the correct offset. */ > #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 > > +#define KVM_DIRTY_LOG_PAGE_OFFSET 64 > + > struct kvm_regs { > __u64 pc; > __u64 cr; > diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig > index 902611954200..c93354ec3bd5 100644 > --- a/arch/powerpc/kvm/Kconfig > +++ b/arch/powerpc/kvm/Kconfig > @@ -26,6 +26,8 @@ config KVM > select IRQ_BYPASS_MANAGER > select HAVE_KVM_IRQ_BYPASS > select INTERVAL_TREE > + select HAVE_KVM_DIRTY_RING_ACQ_REL > + select NEED_KVM_DIRTY_RING_WITH_BITMAP > > config KVM_BOOK3S_HANDLER > bool > diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c > index 7f765d5ad436..c92e8022e017 100644 > --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c > +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c > @@ -2147,3 +2147,45 @@ void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu) > > vcpu->arch.hflags |= BOOK3S_HFLAG_SLB; > } > + > +/* > + * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected > + * dirty pages. > + * > + * It write protects selected pages to enable dirty logging for them. > + */ > +void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, > + struct kvm_memory_slot *slot, > + gfn_t gfn_offset, > + unsigned long mask) > +{ > + phys_addr_t base_gfn = slot->base_gfn + gfn_offset; > + phys_addr_t start = (base_gfn + __ffs(mask)) << PAGE_SHIFT; > + phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT; > + > + while (start < end) { > + pte_t *ptep; > + unsigned int shift; > + > + ptep = find_kvm_secondary_pte(kvm, start, &shift); > + > + *ptep = __pte(pte_val(*ptep) & ~(_PAGE_WRITE)); > + > + start += PAGE_SIZE; > + } > +} > + > +#ifdef CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP > +bool kvm_arch_allow_write_without_running_vcpu(struct kvm *kvm) > +{ > + return true; > +} > +#endif > + > +#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT > +void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, > + const struct kvm_memory_slot *memslot) > +{ > + kvm_flush_remote_tlbs(kvm); > +} > +#endif > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > index 130bafdb1430..1d1264ea72c4 100644 > --- a/arch/powerpc/kvm/book3s_hv.c > +++ b/arch/powerpc/kvm/book3s_hv.c > @@ -4804,6 +4804,9 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu) > return -EINTR; > } > > + if (kvm_dirty_ring_check_request(vcpu)) > + return 0; > + > #ifdef CONFIG_PPC_TRANSACTIONAL_MEM > /* > * Don't allow entry with a suspended transaction, because > diff --git a/include/linux/kvm_dirty_ring.h b/include/linux/kvm_dirty_ring.h > index 4862c98d80d3..a00301059da5 100644 > --- a/include/linux/kvm_dirty_ring.h > +++ b/include/linux/kvm_dirty_ring.h > @@ -69,6 +69,11 @@ static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring) > { > } > > +static inline bool kvm_dirty_ring_check_request(struct kvm_vcpu *vcpu) > +{ > + return false; > +} > + > #else /* CONFIG_HAVE_KVM_DIRTY_RING */ > > int kvm_cpu_dirty_log_size(void); > -- > 2.39.2 >
Hi Everyone, On 2023-06-08 08:34:48, Kautuk Consul wrote: > - Enable CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL as ppc64 is weakly > ordered. > - Enable CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP because the > kvmppc_xive_native_set_attr is called in the context of an ioctl > syscall and will call kvmppc_xive_native_eq_sync for setting the > KVM_DEV_XIVE_EQ_SYNC attribute which will call mark_dirty_page() > when there isn't a running vcpu. Implemented the > kvm_arch_allow_write_without_running_vcpu to always return true > to allow mark_page_dirty_in_slot to mark the page dirty in the > memslot->dirty_bitmap in this case. > - Set KVM_DIRTY_LOG_PAGE_OFFSET for the ring buffer's physical page > offset. > - Implement the kvm_arch_mmu_enable_log_dirty_pt_masked function required > for the generic KVM code to call. > - Add a check to kvmppc_vcpu_run_hv for checking whether the dirty > ring is soft full. > - Implement the kvm_arch_flush_remote_tlbs_memslot function to support > the CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT config option. > > On testing with live migration it was found that there is around > 150-180 ms improvment in overall migration time with this patch. > > Signed-off-by: Kautuk Consul <kconsul@linux.vnet.ibm.com> Can someone review this ?
On 8/6/23 10:34 pm, Kautuk Consul wrote: Need at least a little context in the commit message itself: "Enable ring-based dirty memory tracking on ppc64:" > - Enable CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL as ppc64 is weakly > ordered. > - Enable CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP because the > kvmppc_xive_native_set_attr is called in the context of an ioctl > syscall and will call kvmppc_xive_native_eq_sync for setting the > KVM_DEV_XIVE_EQ_SYNC attribute which will call mark_dirty_page() > when there isn't a running vcpu. Implemented the > kvm_arch_allow_write_without_running_vcpu to always return true > to allow mark_page_dirty_in_slot to mark the page dirty in the > memslot->dirty_bitmap in this case. Should kvm_arch_allow_write_without_running_vcpu() only return true in the context of kvmppc_xive_native_eq_sync()? > - Set KVM_DIRTY_LOG_PAGE_OFFSET for the ring buffer's physical page > offset. > - Implement the kvm_arch_mmu_enable_log_dirty_pt_masked function required > for the generic KVM code to call. > - Add a check to kvmppc_vcpu_run_hv for checking whether the dirty > ring is soft full. > - Implement the kvm_arch_flush_remote_tlbs_memslot function to support > the CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT config option. > > On testing with live migration it was found that there is around > 150-180 ms improvment in overall migration time with this > > Signed-off-by: Kautuk Consul <kconsul@linux.vnet.ibm.com> > --- > Documentation/virt/kvm/api.rst | 2 +- > arch/powerpc/include/uapi/asm/kvm.h | 2 ++ > arch/powerpc/kvm/Kconfig | 2 ++ > arch/powerpc/kvm/book3s_64_mmu_hv.c | 42 +++++++++++++++++++++++++++++ > arch/powerpc/kvm/book3s_hv.c | 3 +++ > include/linux/kvm_dirty_ring.h | 5 ++++ > 6 files changed, 55 insertions(+), 1 deletion(-) > > diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst > index add067793b90..ce1ebc513bae 100644 > --- a/Documentation/virt/kvm/api.rst > +++ b/Documentation/virt/kvm/api.rst > @@ -8114,7 +8114,7 @@ regardless of what has actually been exposed through the CPUID leaf. > 8.29 KVM_CAP_DIRTY_LOG_RING/KVM_CAP_DIRTY_LOG_RING_ACQ_REL > ---------------------------------------------------------- > > -:Architectures: x86, arm64 > +:Architectures: x86, arm64, ppc64 > :Parameters: args[0] - size of the dirty log ring > > KVM is capable of tracking dirty memory using ring buffers that are > diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h > index 9f18fa090f1f..f722309ed7fb 100644 > --- a/arch/powerpc/include/uapi/asm/kvm.h > +++ b/arch/powerpc/include/uapi/asm/kvm.h > @@ -33,6 +33,8 @@ > /* Not always available, but if it is, this is the correct offset. */ > #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 > > +#define KVM_DIRTY_LOG_PAGE_OFFSET 64 > + > struct kvm_regs { > __u64 pc; > __u64 cr; > diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig > index 902611954200..c93354ec3bd5 100644 > --- a/arch/powerpc/kvm/Kconfig > +++ b/arch/powerpc/kvm/Kconfig > @@ -26,6 +26,8 @@ config KVM > select IRQ_BYPASS_MANAGER > select HAVE_KVM_IRQ_BYPASS > select INTERVAL_TREE > + select HAVE_KVM_DIRTY_RING_ACQ_REL > + select NEED_KVM_DIRTY_RING_WITH_BITMAP > > config KVM_BOOK3S_HANDLER > bool > diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c > index 7f765d5ad436..c92e8022e017 100644 > --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c > +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c > @@ -2147,3 +2147,45 @@ void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu) > > vcpu->arch.hflags |= BOOK3S_HFLAG_SLB; > } > + > +/* > + * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected > + * dirty pages. > + * > + * It write protects selected pages to enable dirty logging for them. > + */ > +void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, > + struct kvm_memory_slot *slot, > + gfn_t gfn_offset, > + unsigned long mask) > +{ > + phys_addr_t base_gfn = slot->base_gfn + gfn_offset; > + phys_addr_t start = (base_gfn + __ffs(mask)) << PAGE_SHIFT; > + phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT; > + > + while (start < end) { > + pte_t *ptep; > + unsigned int shift; > + > + ptep = find_kvm_secondary_pte(kvm, start, &shift); > + > + *ptep = __pte(pte_val(*ptep) & ~(_PAGE_WRITE)); On rpt I think you'd need to use kvmppc_radix_update_pte()? > + > + start += PAGE_SIZE > + } > +} > + > +#ifdef CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP > +bool kvm_arch_allow_write_without_running_vcpu(struct kvm *kvm) > +{ > + return true; > +} > +#endif > + > +#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT > +void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, > + const struct kvm_memory_slot *memslot) > +{ > + kvm_flush_remote_tlbs(kvm); > +} > +#endif > diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c > index 130bafdb1430..1d1264ea72c4 100644 > --- a/arch/powerpc/kvm/book3s_hv.c > +++ b/arch/powerpc/kvm/book3s_hv.c > @@ -4804,6 +4804,9 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu) > return -EINTR; > } > > + if (kvm_dirty_ring_check_request(vcpu)) > + return 0; > + > #ifdef CONFIG_PPC_TRANSACTIONAL_MEM > /* > * Don't allow entry with a suspended transaction, because > diff --git a/include/linux/kvm_dirty_ring.h b/include/linux/kvm_dirty_ring.h > index 4862c98d80d3..a00301059da5 100644 > --- a/include/linux/kvm_dirty_ring.h > +++ b/include/linux/kvm_dirty_ring.h > @@ -69,6 +69,11 @@ static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring) > { > } > > +static inline bool kvm_dirty_ring_check_request(struct kvm_vcpu *vcpu) > +{ > + return false; > +} > + > #else /* CONFIG_HAVE_KVM_DIRTY_RING */ > > int kvm_cpu_dirty_log_size(void); >
Hi Jordan, On 2023-07-06 14:15:13, Jordan Niethe wrote: > > > On 8/6/23 10:34 pm, Kautuk Consul wrote: > > Need at least a little context in the commit message itself: > > "Enable ring-based dirty memory tracking on ppc64:" Sure will take this in the v2 patch. > > > - Enable CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL as ppc64 is weakly > > ordered. > > - Enable CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP because the > > kvmppc_xive_native_set_attr is called in the context of an ioctl > > syscall and will call kvmppc_xive_native_eq_sync for setting the > > KVM_DEV_XIVE_EQ_SYNC attribute which will call mark_dirty_page() > > when there isn't a running vcpu. Implemented the > > kvm_arch_allow_write_without_running_vcpu to always return true > > to allow mark_page_dirty_in_slot to mark the page dirty in the > > memslot->dirty_bitmap in this case. > > Should kvm_arch_allow_write_without_running_vcpu() only return true in the > context of kvmppc_xive_native_eq_sync()? Not required. Reason is: kvm_arch_allow_write_without_running_vcpu() is anyway used only for avoiding the WARN_ON_ONCE in mark_page_dirty_in_slot(). The memslot->dirty_bitmap in mark_page_dirty_in_slot() will be anyway used only when the KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP is set and the vcpu returned by kvm_get_running_vcpu() is NULL which is what happens only when kvmppc_xive_native_eq_sync is called via the ioctl syscall I mentioned. > > + *ptep = __pte(pte_val(*ptep) & ~(_PAGE_WRITE)); > On rpt I think you'd need to use kvmppc_radix_update_pte()? Sure. I'll add a check for radix_enabled() and call kvmppc_radix_update_pte() or a similar function in the v2 patch for this.
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index add067793b90..ce1ebc513bae 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -8114,7 +8114,7 @@ regardless of what has actually been exposed through the CPUID leaf. 8.29 KVM_CAP_DIRTY_LOG_RING/KVM_CAP_DIRTY_LOG_RING_ACQ_REL ---------------------------------------------------------- -:Architectures: x86, arm64 +:Architectures: x86, arm64, ppc64 :Parameters: args[0] - size of the dirty log ring KVM is capable of tracking dirty memory using ring buffers that are diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h index 9f18fa090f1f..f722309ed7fb 100644 --- a/arch/powerpc/include/uapi/asm/kvm.h +++ b/arch/powerpc/include/uapi/asm/kvm.h @@ -33,6 +33,8 @@ /* Not always available, but if it is, this is the correct offset. */ #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 +#define KVM_DIRTY_LOG_PAGE_OFFSET 64 + struct kvm_regs { __u64 pc; __u64 cr; diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig index 902611954200..c93354ec3bd5 100644 --- a/arch/powerpc/kvm/Kconfig +++ b/arch/powerpc/kvm/Kconfig @@ -26,6 +26,8 @@ config KVM select IRQ_BYPASS_MANAGER select HAVE_KVM_IRQ_BYPASS select INTERVAL_TREE + select HAVE_KVM_DIRTY_RING_ACQ_REL + select NEED_KVM_DIRTY_RING_WITH_BITMAP config KVM_BOOK3S_HANDLER bool diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 7f765d5ad436..c92e8022e017 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -2147,3 +2147,45 @@ void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu) vcpu->arch.hflags |= BOOK3S_HFLAG_SLB; } + +/* + * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected + * dirty pages. + * + * It write protects selected pages to enable dirty logging for them. + */ +void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, + struct kvm_memory_slot *slot, + gfn_t gfn_offset, + unsigned long mask) +{ + phys_addr_t base_gfn = slot->base_gfn + gfn_offset; + phys_addr_t start = (base_gfn + __ffs(mask)) << PAGE_SHIFT; + phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT; + + while (start < end) { + pte_t *ptep; + unsigned int shift; + + ptep = find_kvm_secondary_pte(kvm, start, &shift); + + *ptep = __pte(pte_val(*ptep) & ~(_PAGE_WRITE)); + + start += PAGE_SIZE; + } +} + +#ifdef CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP +bool kvm_arch_allow_write_without_running_vcpu(struct kvm *kvm) +{ + return true; +} +#endif + +#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT +void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, + const struct kvm_memory_slot *memslot) +{ + kvm_flush_remote_tlbs(kvm); +} +#endif diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 130bafdb1430..1d1264ea72c4 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -4804,6 +4804,9 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu) return -EINTR; } + if (kvm_dirty_ring_check_request(vcpu)) + return 0; + #ifdef CONFIG_PPC_TRANSACTIONAL_MEM /* * Don't allow entry with a suspended transaction, because diff --git a/include/linux/kvm_dirty_ring.h b/include/linux/kvm_dirty_ring.h index 4862c98d80d3..a00301059da5 100644 --- a/include/linux/kvm_dirty_ring.h +++ b/include/linux/kvm_dirty_ring.h @@ -69,6 +69,11 @@ static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring) { } +static inline bool kvm_dirty_ring_check_request(struct kvm_vcpu *vcpu) +{ + return false; +} + #else /* CONFIG_HAVE_KVM_DIRTY_RING */ int kvm_cpu_dirty_log_size(void);
- Enable CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL as ppc64 is weakly ordered. - Enable CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP because the kvmppc_xive_native_set_attr is called in the context of an ioctl syscall and will call kvmppc_xive_native_eq_sync for setting the KVM_DEV_XIVE_EQ_SYNC attribute which will call mark_dirty_page() when there isn't a running vcpu. Implemented the kvm_arch_allow_write_without_running_vcpu to always return true to allow mark_page_dirty_in_slot to mark the page dirty in the memslot->dirty_bitmap in this case. - Set KVM_DIRTY_LOG_PAGE_OFFSET for the ring buffer's physical page offset. - Implement the kvm_arch_mmu_enable_log_dirty_pt_masked function required for the generic KVM code to call. - Add a check to kvmppc_vcpu_run_hv for checking whether the dirty ring is soft full. - Implement the kvm_arch_flush_remote_tlbs_memslot function to support the CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT config option. On testing with live migration it was found that there is around 150-180 ms improvment in overall migration time with this patch. Signed-off-by: Kautuk Consul <kconsul@linux.vnet.ibm.com> --- Documentation/virt/kvm/api.rst | 2 +- arch/powerpc/include/uapi/asm/kvm.h | 2 ++ arch/powerpc/kvm/Kconfig | 2 ++ arch/powerpc/kvm/book3s_64_mmu_hv.c | 42 +++++++++++++++++++++++++++++ arch/powerpc/kvm/book3s_hv.c | 3 +++ include/linux/kvm_dirty_ring.h | 5 ++++ 6 files changed, 55 insertions(+), 1 deletion(-)