[PATCH v4 00/14] KVM/X86: Introduce a new guest mapping interface

From: KarimAllah Ahmed
Date: Mon Dec 03 2018 - 04:33:15 EST


Guest memory can either be directly managed by the kernel (i.e. have a "struct
page") or they can simply live outside kernel control (i.e. do not have a
"struct page"). KVM mostly support these two modes, except in a few places
where the code seems to assume that guest memory must have a "struct page".

This patchset introduces a new mapping interface to map guest memory into host
kernel memory which also supports PFN-based memory (i.e. memory without 'struct
page'). It also converts all offending code to this interface or simply
read/write directly from guest memory.

As far as I can see all offending code is now fixed except the APIC-access page
which I will handle in a seperate series along with dropping
kvm_vcpu_gfn_to_page and kvm_vcpu_gpa_to_page from the internal KVM API.

The current implementation of the new API uses memremap to map memory that does
not have a "struct page". This proves to be very slow for high frequency
mappings. Since this does not affect the normal use-case where a "struct page"
is available, the performance of this API will be handled by a seperate patch
series.

v3 -> v4:
- Rebase
- Add a new patch to also fix the newly introduced enhanced VMCS.

v2 -> v3:
- Rebase
- Add a new patch to also fix the newly introduced shadow VMCS.

Filippo Sironi (1):
X86/KVM: Handle PFNs outside of kernel reach when touching GPTEs

KarimAllah Ahmed (13):
X86/nVMX: handle_vmon: Read 4 bytes from guest memory
X86/nVMX: handle_vmptrld: Copy the VMCS12 directly from guest memory
X86/nVMX: Update the PML table without mapping and unmapping the page
KVM: Introduce a new guest mapping API
KVM/nVMX: Use kvm_vcpu_map when mapping the L1 MSR bitmap
KVM/nVMX: Use kvm_vcpu_map when mapping the virtual APIC page
KVM/nVMX: Use kvm_vcpu_map when mapping the posted interrupt
descriptor table
KVM/X86: Use kvm_vcpu_map in emulator_cmpxchg_emulated
KVM/X86: hyperv: Use kvm_vcpu_map in synic_clear_sint_msg_pending
KVM/X86: hyperv: Use kvm_vcpu_map in synic_deliver_msg
KVM/nSVM: Use the new mapping API for mapping guest memory
KVM/nVMX: Use kvm_vcpu_map for accessing the shadow VMCS
KVM/nVMX: Use kvm_vcpu_map for accessing the enhanced VMCS

arch/x86/kvm/hyperv.c | 28 +++----
arch/x86/kvm/paging_tmpl.h | 38 ++++++---
arch/x86/kvm/svm.c | 97 +++++++++++------------
arch/x86/kvm/vmx.c | 189 +++++++++++++++++----------------------------
arch/x86/kvm/x86.c | 13 ++--
include/linux/kvm_host.h | 9 +++
virt/kvm/kvm_main.c | 50 ++++++++++++
7 files changed, 228 insertions(+), 196 deletions(-)

--
2.7.4