[PATCH v3 00/40] KVM: x86: GPR accessors and x86.{c,h} spring cleaning
From: Sean Christopherson
Date: Fri May 29 2026 - 18:26:16 EST
The first half of this series adds proper, explicit "raw" versions of
kvm_<reg>_{read,write}(), along with "e" versions (for hardcoded 32-bit
accesses), and converts the existing kvm_<reg>_{read,write}() APIs into
mode-aware variants.
At the end of that journey, introduce regs.{c,h} to avoid moving _more_ code
into x86.h, especially since the resulting code split would be super arbitrary.
The second half of the series runs with the regs.{c,h} changes and performs
spring cleaning on x86.{c,h} and asm/kvm_host.h (in case it wasn't already
obvious, I have poor impulse control when it comes to cleaning up code).
I'm most intersted in getting feedback on the file names (regs.{c,h} and
msrs.{c,h}. I'm quite confident the actual code split is the way to go, and
pulling stuff out of asm/kvm_host.h has been on my wish/todo list for years.
I'll grab these fixes for 7.2 no matter what:
KVM: x86: Trace hypercall register *after* truncating values for 32-bit
KVM: VMX: Read 32-bit GPR values for ENCLS instructions outside of 64-bit mode
KVM: x86/xen: Don't truncate RAX when handling hypercall from protected guest
KVM: x86/xen: Bug the VM if 32-bit KVM observes a 64-bit mode hypercall
Depending on how people feel about the names and cleanups, I'll either send
the big cleanups as a separate pull request after the initial for-7.2 pull
requests (if there's overwhelming consensus on the names/splits), or wait for
7.3 (if more discussion is needed).
v3:
- Collect more tags. [David, Binbin, Yosry]
- Use kvm_run_sync_regs_{from,to}_user() instead of kvm_run_{g,s}et_regs().
[Kai]
- Fix a variety of typos. [Binbin]
- Everything beyond patch 15...
v2:
- https://lore.kernel.org/all/20260514215355.1648463-2-seanjc@xxxxxxxxxx
- Collect tags. [Yosry, Kai]
- Fix some truly egregious goofs. [Binbin]
- Rename kvm_cache_regs.h => regs.h, add regs.c. [Yosry, because he
complained, not because he actually suggested this :-D ]
- Drop superfluous casting/masking of e*x() usage. [Kai]
v1: https://lore.kernel.org/all/20260409235622.2052730-1-seanjc@xxxxxxxxxx
Sean Christopherson (40):
KVM: SVM: Truncate INVLPGA address in compatibility mode
KVM: x86/xen: Bug the VM if 32-bit KVM observes a 64-bit mode
hypercall
KVM: x86/xen: Don't truncate RAX when handling hypercall from
protected guest
KVM: VMX: Read 32-bit GPR values for ENCLS instructions outside of
64-bit mode
KVM: x86: Trace hypercall register *after* truncating values for
32-bit
KVM: x86: Rename kvm_cache_regs.h => regs.h
KVM: x86: Move inlined GPR, CR, and DR helpers from x86.h to regs.h
KVM: x86: Add mode-aware versions of kvm_<reg>_{read,write}() helpers
KVM: x86: Drop non-raw kvm_<reg>_write() helpers
KVM: nSVM: Use kvm_rax_read() now that it's mode-aware
Revert "KVM: VMX: Read 32-bit GPR values for ENCLS instructions
outside of 64-bit mode"
KVM: x86: Harden is_64_bit_hypercall() against bugs on 32-bit kernels
KVM: x86: Move update_cr8_intercept() to lapic.c
KVM: x86: Move async #PF helpers to x86.h (as inlines)
KVM: x86: Move the bulk of register specific code from x86.c to regs.c
KVM: x86: Move local APIC specific helpers out of asm/kvm_host.h
KVM: x86: Drop defunct vcpu_tsc_khz() declaration
KVM: x86: Move kvm_caps and kvm_host_values to asm/kvm_host.h
KVM: x86: Swap the include order between x86.h and mmu.h
KVM: x86: Move tdp_enabled from kvm_host.h to mmu.h
KVM: x86: Move eager_page_split to mmu.{c,h}
KVM: x86/hyperv: Eliminate an unnecessary include of x86.h in hyperv.h
KVM: x86: Move kvm_{load,put}_guest_fpu() to fpu.h
KVM: x86: Extract get/set MSR (list) ioctl logic to helpers
KVM: x86: Expose several TSC helpers via x86.h for use by MSR code
KVM: x86: Move the bulk of MSR specific code from x86.c to msrs.{c,h}
KVM: x86: Move register helper declarations from kvm_host.h => regs.h
KVM: x86: Move kvm_{g,s}et_segment() to inline helpers in regs.h
KVM: x86: Remove defunct kvm_load_segment_descriptor() declaration.
KVM: x86: Move MSR helper declarations from kvm_host.h => msrs.h
KVM: x86: Move MMU helper declarations from kvm_host.h => mmu.h
KVM: x86: Move LLDT assembly wrappers into VMX
KVM: x86: Move kvm_cpu_get_apicid() from kvm_host.h => avic.c
KVM: x86: Move misc "VALID MASK" defines from kvm_host.h => x86.c
KVM: x86: Move __kvm_irq_line_state() from kvm_host.h => ioapic.h
KVM: x86: Move IRQ-related helper declarations from kvm_host.h =>
irq.h
KVM: x86: Move kvm_pv_send_ipi() declaration from kvm_host.h =>
lapic.h
KVM: x86/mmu: Move kvm_arch_async_page_ready() below
kvm_tdp_page_fault()
KVM: x86/mmu: Move kvm_mmu_do_page_fault() from mmu_internal.h =>
mmu.c
KVM: x86: Move a pile of stuff from kvm_host.h => x86.h
arch/x86/include/asm/kvm_host.h | 452 +--
arch/x86/kvm/Makefile | 4 +-
arch/x86/kvm/cpuid.c | 13 +-
arch/x86/kvm/emulate.c | 2 +-
arch/x86/kvm/fpu.h | 26 +
arch/x86/kvm/hyperv.c | 21 +-
arch/x86/kvm/hyperv.h | 7 +-
arch/x86/kvm/ioapic.c | 1 +
arch/x86/kvm/ioapic.h | 12 +
arch/x86/kvm/irq.c | 7 +
arch/x86/kvm/irq.h | 6 +
arch/x86/kvm/lapic.c | 28 +-
arch/x86/kvm/lapic.h | 9 +
arch/x86/kvm/mmu.h | 92 +-
arch/x86/kvm/mmu/mmu.c | 134 +-
arch/x86/kvm/mmu/mmu_internal.h | 66 -
arch/x86/kvm/msrs.c | 2732 +++++++++++++++
arch/x86/kvm/msrs.h | 156 +
arch/x86/kvm/mtrr.c | 1 +
arch/x86/kvm/regs.c | 875 +++++
arch/x86/kvm/{kvm_cache_regs.h => regs.h} | 258 +-
arch/x86/kvm/smm.c | 2 +-
arch/x86/kvm/svm/avic.c | 5 +
arch/x86/kvm/svm/nested.c | 9 +-
arch/x86/kvm/svm/svm.c | 19 +-
arch/x86/kvm/svm/svm.h | 2 +-
arch/x86/kvm/vmx/nested.c | 9 +-
arch/x86/kvm/vmx/nested.h | 2 +-
arch/x86/kvm/vmx/sgx.c | 6 +-
arch/x86/kvm/vmx/tdx.c | 18 +-
arch/x86/kvm/vmx/vmx.c | 14 +-
arch/x86/kvm/vmx/vmx.h | 2 +-
arch/x86/kvm/x86.c | 3789 +--------------------
arch/x86/kvm/x86.h | 480 ++-
arch/x86/kvm/xen.c | 39 +-
35 files changed, 4722 insertions(+), 4576 deletions(-)
create mode 100644 arch/x86/kvm/msrs.c
create mode 100644 arch/x86/kvm/msrs.h
create mode 100644 arch/x86/kvm/regs.c
rename arch/x86/kvm/{kvm_cache_regs.h => regs.h} (50%)
base-commit: d1568b1332b6b3b36b222c2868fc102727c12a34
--
2.54.0.823.g6e5bcc1fc9-goog