linux/arch/x86
Sean Christopherson ccd85d90ce KVM: SVM: Treat SVM as unsupported when running as an SEV guest
Don't let KVM load when running as an SEV guest, regardless of what
CPUID says.  Memory is encrypted with a key that is not accessible to
the host (L0), thus it's impossible for L0 to emulate SVM, e.g. it'll
see garbage when reading the VMCB.

Technically, KVM could decrypt all memory that needs to be accessible to
the L0 and use shadow paging so that L0 does not need to shadow NPT, but
exposing such information to L0 largely defeats the purpose of running as
an SEV guest.  This can always be revisited if someone comes up with a
use case for running VMs inside SEV guests.

Note, VMLOAD, VMRUN, etc... will also #GP on GPAs with C-bit set, i.e. KVM
is doomed even if the SEV guest is debuggable and the hypervisor is willing
to decrypt the VMCB.  This may or may not be fixed on CPUs that have the
SVME_ADDR_CHK fix.

Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210202212017.2486595-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-03 04:30:37 -05:00
..
boot EFI updates collected by Ard Biesheuvel: 2020-12-24 12:40:07 -08:00
configs
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2020-12-14 12:18:19 -08:00
entry epoll: wire up syscall epoll_pwait2 2020-12-19 11:18:38 -08:00
events Perf updates: 2020-12-14 17:34:12 -08:00
hyperv
ia32 x86/ia32_signal: Propagate __user annotation properly 2020-12-11 19:44:31 +01:00
include x86: 2021-01-08 15:06:02 -08:00
kernel x86/resctrl: Don't move a task to the same resource group 2021-01-08 09:08:03 +01:00
kvm KVM: SVM: Treat SVM as unsupported when running as an SEV guest 2021-02-03 04:30:37 -05:00
lib Scheduler updates: 2020-12-14 18:29:11 -08:00
math-emu
mm KVM: SVM: Treat SVM as unsupported when running as an SEV guest 2021-02-03 04:30:37 -05:00
net
oprofile
pci ARM: SoC drivers for v5.11 2020-12-16 16:38:41 -08:00
platform Yet another large set of x86 interrupt management updates: 2020-12-14 18:59:53 -08:00
power
purgatory crypto: sha - split sha.h into sha1.h and sha2.h 2020-11-20 14:45:33 +11:00
ras
realmode
tools
um
video
xen EFI updates collected by Ard Biesheuvel: 2020-12-24 12:40:07 -08:00
.gitignore
Kbuild
Kconfig fanotify: Fix sys_fanotify_mark() on native x86-32 2020-12-28 11:58:59 +01:00
Kconfig.assembler
Kconfig.cpu
Kconfig.debug
Makefile - Fix the vmlinux size check on 64-bit along with adding useful clarifications on the topic 2020-12-14 13:54:50 -08:00
Makefile.um
Makefile_32.cpu