linux_dsm_epyc7002/arch/x86
Sean Christopherson ff0c437a0e KVM: SVM: Treat SVM as unsupported when running as an SEV guest
commit ccd85d90ce092bdb047a7f6580f3955393833b22 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-10 09:29:19 +01:00
..
boot A set of fixes for x86: 2020-12-06 11:22:39 -08:00
configs * A defconfig fix, from Daniel Díaz. 2020-09-20 15:06:43 -07:00
crypto crypto: x86/poly1305 - add back a needed assignment 2020-10-24 09:38:32 +11:00
entry x86/entry: Emit a symbol for register restoring thunk 2021-02-03 23:28:40 +01:00
events perf/x86/intel/lbr: Fix the return type of get_lbr_cycles() 2020-12-30 11:54:10 +01:00
hyperv x86/hyperv: Fix kexec panic/hang issues 2021-01-27 11:54:57 +01:00
ia32 x86: remove address space overrides using set_fs() 2020-09-08 22:21:36 -04:00
include x86/cpu: Add another Alder Lake CPU to the Intel family 2021-02-07 15:37:17 +01:00
kernel Revert "x86/setup: don't remove E820_TYPE_RAM for pfn 0" 2021-02-07 15:37:13 +01:00
kvm KVM: SVM: Treat SVM as unsupported when running as an SEV guest 2021-02-10 09:29:19 +01:00
lib x86/mmx: Use KFPU_387 for MMX string operations 2021-01-27 11:55:13 +01:00
math-emu treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
mm KVM: SVM: Treat SVM as unsupported when running as an SEV guest 2021-02-10 09:29:19 +01:00
net bpf: x64: Do not emit sub/add 0, %rsp when !stack_depth 2020-09-29 16:47:39 -07:00
oprofile
pci pci-v5.10-changes 2020-10-22 12:41:00 -07:00
platform efi/x86: Free efi_pgd with free_pages() 2020-11-10 19:18:11 +01:00
power Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
purgatory treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
ras
realmode x86/head/64: Don't call verify_cpu() on starting APs 2020-09-09 11:33:20 +02:00
tools x86/insn: Make inat-tables.c suitable for pre-decompression code 2020-09-07 19:45:24 +02:00
um arch/um: partially revert the conversion to __section() macro 2020-10-26 15:39:37 -07:00
video
xen x86/xen: avoid warning in Xen pv guest with CONFIG_AMD_MEM_ENCRYPT enabled 2021-02-03 23:28:38 +01:00
.gitignore
Kbuild
Kconfig fanotify: Fix sys_fanotify_mark() on native x86-32 2021-01-17 14:16:59 +01:00
Kconfig.assembler
Kconfig.cpu
Kconfig.debug x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}() 2020-10-06 11:18:04 +02:00
Makefile kbuild: Hoist '--orphan-handling' into Kconfig 2020-12-01 22:45:36 +09:00
Makefile_32.cpu
Makefile.um