mirror of
https://git.proxmox.com/git/mirror_ubuntu-kernels.git
synced 2026-02-06 03:15:46 +00:00
8dd2eee9d5
Add support for resolving page faults on guest private memory for VMs that differentiate between "shared" and "private" memory. For such VMs, KVM_MEM_GUEST_MEMFD memslots can include both fd-based private memory and hva-based shared memory, and KVM needs to map in the "correct" variant, i.e. KVM needs to map the gfn shared/private as appropriate based on the current state of the gfn's KVM_MEMORY_ATTRIBUTE_PRIVATE flag. For AMD's SEV-SNP and Intel's TDX, the guest effectively gets to request shared vs. private via a bit in the guest page tables, i.e. what the guest wants may conflict with the current memory attributes. To support such "implicit" conversion requests, exit to user with KVM_EXIT_MEMORY_FAULT to forward the request to userspace. Add a new flag for memory faults, KVM_MEMORY_EXIT_FLAG_PRIVATE, to communicate whether the guest wants to map memory as shared vs. private. Like KVM_MEMORY_ATTRIBUTE_PRIVATE, use bit 3 for flagging private memory so that KVM can use bits 0-2 for capturing RWX behavior if/when userspace needs such information, e.g. a likely user of KVM_EXIT_MEMORY_FAULT is to exit on missing mappings when handling guest page fault VM-Exits. In that case, userspace will want to know RWX information in order to correctly/precisely resolve the fault. Note, private memory *must* be backed by guest_memfd, i.e. shared mappings always come from the host userspace page tables, and private mappings always come from a guest_memfd instance. Co-developed-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com> Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Message-Id: <20231027182217.3615211-21-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
||
|---|---|---|
| .. | ||
| asm-generic | ||
| drm | ||
| linux | ||
| misc | ||
| mtd | ||
| rdma | ||
| scsi | ||
| sound | ||
| video | ||
| xen | ||
| Kbuild | ||