linux/arch
Sean Christopherson 09e3e2a1cc KVM: x86: Add kvm_x86_ops hook to short circuit emulation
Replace the existing kvm_x86_ops.need_emulation_on_page_fault() with a
more generic is_emulatable(), and unconditionally call the new function
in x86_emulate_instruction().

KVM will use the generic hook to support multiple security related
technologies that prevent emulation in one way or another.  Similar to
the existing AMD #NPF case where emulation of the current instruction is
not possible due to lack of information, AMD's SEV-ES and Intel's SGX
and TDX will introduce scenarios where emulation is impossible due to
the guest's register state being inaccessible.  And again similar to the
existing #NPF case, emulation can be initiated by kvm_mmu_page_fault(),
i.e. outside of the control of vendor-specific code.

While the cause and architecturally visible behavior of the various
cases are different, e.g. SGX will inject a #UD, AMD #NPF is a clean
resume or complete shutdown, and SEV-ES and TDX "return" an error, the
impact on the common emulation code is identical: KVM must stop
emulation immediately and resume the guest.

Query is_emulatable() in handle_ud() as well so that the
force_emulation_prefix code doesn't incorrectly modify RIP before
calling emulate_instruction() in the absurdly unlikely scenario that
KVM encounters forced emulation in conjunction with "do not emulate".

Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200915232702.15945-1-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28 07:57:19 -04:00
..
alpha treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
arc ARC fixes for 5.9-rc4 2020-09-05 13:46:14 -07:00
arm A set of fixes for lockdep, tracing and RCU: 2020-08-30 11:43:50 -07:00
arm64 Merge branch 'x86-seves-for-paolo' of https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into HEAD 2020-09-22 06:43:17 -04:00
c6x treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
csky treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
h8300 treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
hexagon treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
ia64 ia64: fix min_low_pfn/max_low_pfn build errors 2020-09-01 19:34:11 +03:00
m68k treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
microblaze microblaze: fix min_low_pfn/max_low_pfn build errors 2020-08-31 19:52:50 +03:00
mips Merge branch 'x86-seves-for-paolo' of https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into HEAD 2020-09-22 06:43:17 -04:00
nds32 A set of fixes for lockdep, tracing and RCU: 2020-08-30 11:43:50 -07:00
nios2 mm/nios2: use general page fault accounting 2020-08-12 10:58:03 -07:00
openrisc treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
parisc treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
powerpc PPC KVM update for 5.10 2020-09-22 08:18:16 -04:00
riscv treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
s390 s390: update defconfigs 2020-09-02 13:17:05 +02:00
sh treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
sparc treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
um treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
x86 KVM: x86: Add kvm_x86_ops hook to short circuit emulation 2020-09-28 07:57:19 -04:00
xtensa treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
.gitignore
Kconfig A set oftimekeeping/VDSO updates: 2020-08-14 14:26:08 -07:00