diff options
Diffstat (limited to 'Documentation/virtual/kvm/api.txt')
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 33 |
1 files changed, 25 insertions, 8 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index bf33aaa4c59f..f6ec3a92e621 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -857,7 +857,8 @@ struct kvm_userspace_memory_region { }; /* for kvm_memory_region::flags */ -#define KVM_MEM_LOG_DIRTY_PAGES 1UL +#define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) +#define KVM_MEM_READONLY (1UL << 1) 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 @@ -873,14 +874,17 @@ 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 just one flag, KVM_MEM_LOG_DIRTY_PAGES, which -instructs kvm to keep track of writes to memory within the slot. See -the KVM_GET_DIRTY_LOG ioctl. +The flags field supports two flag, KVM_MEM_LOG_DIRTY_PAGES, which instructs +kvm to keep track of writes to memory within the slot. See KVM_GET_DIRTY_LOG +ioctl. The KVM_CAP_READONLY_MEM capability indicates the availability of the +KVM_MEM_READONLY flag. When this flag is set for a memory region, KVM only +allows read accesses. Writes will be posted to userspace as KVM_EXIT_MMIO +exits. -When the KVM_CAP_SYNC_MMU capability, changes in the backing of the memory -region are automatically reflected into the guest. For example, an mmap() -that affects the region will be made visible immediately. Another example -is madvise(MADV_DROP). +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 +mmap() that affects the region will be made visible immediately. Another +example is madvise(MADV_DROP). It is recommended to use this API instead of the KVM_SET_MEMORY_REGION ioctl. The KVM_SET_MEMORY_REGION does not allow fine grained control over memory @@ -1946,6 +1950,19 @@ the guest using the specified gsi pin. The irqfd is removed using the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd and kvm_irqfd.gsi. +With KVM_CAP_IRQFD_RESAMPLE, KVM_IRQFD supports a de-assert and notify +mechanism allowing emulation of level-triggered, irqfd-based +interrupts. When KVM_IRQFD_FLAG_RESAMPLE is set the user must pass an +additional eventfd in the kvm_irqfd.resamplefd field. When operating +in resample mode, posting of an interrupt through kvm_irq.fd asserts +the specified gsi in the irqchip. When the irqchip is resampled, such +as from an EOI, the gsi is de-asserted and the user is notifed via +kvm_irqfd.resamplefd. It is the user's responsibility to re-queue +the interrupt if the device making use of it still requires service. +Note that closing the resamplefd is not sufficient to disable the +irqfd. The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment +and need not be specified with KVM_IRQFD_FLAG_DEASSIGN. + 4.76 KVM_PPC_ALLOCATE_HTAB Capability: KVM_CAP_PPC_ALLOC_HTAB |