Add proper, explicit "raw" versions of kvm_<reg>_{read,write}(), along
with "e" versions (for hardcoded 32-bit accesses), and convert the
existing kvm_<reg>_{read,write}() APIs into mode-aware variants.
This was prompted by commit 435741a4e766 ("KVM: SVM: Properly check RAX
on #GP intercept of SVM instructions"), where using kvm_rax_read() to
get EAX/RAX would have (*very* surprisingly) been wrong as it's actually
a "raw" variant that doesn't truncate accesses when the guest is in 32-bit
mode.
Aside from my dislike of inconsistent APIs, I really want to avoid carrying
code that's subtly relying on using kvm_register_read(...) when accessing a
hardcoded register.
Fix a handful of minor warts along the way.
Oh, and introduce regs.{c,h}, which just a "minor" addendum. Yosry pointed
out that moving _more_ code into x86.h was rather gross (especially since the
code split was super arbitrary), and it turns out that create regs.{c,h} isn't
all that hard. In the future, I think we can also add msr.{c,h}, so I very
deliberately didn't include that functionality in regs.{c,h}.
v2:
- Collect tags. [Yosry, Kai
- Fix some truly egregious goofs. [Binbin]
- Rename kvm_cache_regs.h => regs.h, add regs.c. [Yosry, though he'll
probably yell at me for saying this was his suggestion :-) ]
- Drop superfluous casting/masking of e*x() usage. [Kai]
v1: https://lore.kernel.org/all/20260409235622.2052730-1-seanjc@google.com
Sean Christopherson (15):
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 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 kvm_pv_async_pf_enabled() to x86.h (as an inline)
KVM: x86: Move the bulk of register specific code from x86.c to regs.c
arch/x86/include/asm/kvm_host.h | 2 -
arch/x86/kvm/Makefile | 4 +-
arch/x86/kvm/cpuid.c | 12 +-
arch/x86/kvm/emulate.c | 2 +-
arch/x86/kvm/hyperv.c | 21 +-
arch/x86/kvm/hyperv.h | 4 +-
arch/x86/kvm/lapic.c | 28 +-
arch/x86/kvm/lapic.h | 1 +
arch/x86/kvm/mmu.h | 2 +-
arch/x86/kvm/mmu/mmu.c | 2 +-
arch/x86/kvm/regs.c | 829 +++++++++++++++++++
arch/x86/kvm/{kvm_cache_regs.h => regs.h} | 203 ++++-
arch/x86/kvm/smm.c | 2 +-
arch/x86/kvm/svm/nested.c | 8 +-
arch/x86/kvm/svm/svm.c | 19 +-
arch/x86/kvm/svm/svm.h | 2 +-
arch/x86/kvm/vmx/nested.c | 8 +-
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 | 2 +-
arch/x86/kvm/vmx/vmx.h | 2 +-
arch/x86/kvm/x86.c | 935 +---------------------
arch/x86/kvm/x86.h | 116 +--
arch/x86/kvm/xen.c | 39 +-
25 files changed, 1162 insertions(+), 1107 deletions(-)
create mode 100644 arch/x86/kvm/regs.c
rename arch/x86/kvm/{kvm_cache_regs.h => regs.h} (58%)
base-commit: a9512a611bd030088f13477258d1f8103cceaa40
--
2.54.0.563.g4f69b47b94-goog