linux_dsm_epyc7002/arch/x86
Oliver Upton 66570e966d kvm: x86: only provide PV features if enabled in guest's CPUID
KVM unconditionally provides PV features to the guest, regardless of the
configured CPUID. An unwitting guest that doesn't check
KVM_CPUID_FEATURES before use could access paravirt features that
userspace did not intend to provide. Fix this by checking the guest's
CPUID before performing any paravirtual operations.

Introduce a capability, KVM_CAP_ENFORCE_PV_FEATURE_CPUID, to gate the
aforementioned enforcement. Migrating a VM from a host w/o this patch to
a host with this patch could silently change the ABI exposed to the
guest, warranting that we default to the old behavior and opt-in for
the new one.

Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Change-Id: I202a0926f65035b872bfe8ad15307c026de59a98
Message-Id: <20200818152429.1923996-4-oupton@google.com>
Reviewed-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-21 17:36:32 -04:00
..
boot Merge 'x86/kaslr' to pick up dependent bits 2020-09-07 18:09:43 +02:00
configs x86/defconfigs: Refresh defconfig files 2020-07-25 12:02:14 +02:00
crypto crypto: x86/curve25519 - Remove unused carry variables 2020-07-31 18:25:29 +10:00
entry x86/entry: Unbreak 32bit fast syscall 2020-09-04 15:50:14 +02:00
events treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
hyperv vmalloc: fix the owner argument for the new __vmalloc_node_range callers 2020-07-03 16:15:25 -07:00
ia32 mm: remove unneeded includes of <asm/pgalloc.h> 2020-08-07 11:33:26 -07:00
include kvm: x86: only provide PV features if enabled in guest's CPUID 2020-10-21 17:36:32 -04:00
kernel cpuidle-haltpoll: fix error comments in arch_haltpoll_disable 2020-09-28 07:57:28 -04:00
kvm kvm: x86: only provide PV features if enabled in guest's CPUID 2020-10-21 17:36:32 -04:00
lib x86/cmdline: Disable jump tables for cmdline.c 2020-09-03 10:59:16 +02:00
math-emu treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
mm x86/kvm: Update the comment about asynchronous page fault in exc_page_fault() 2020-10-21 17:36:31 -04:00
net bpf, i386: Remove unneeded conversion to bool 2020-05-07 16:29:14 +02:00
oprofile
pci xen: branch for v5.9-rc2 2020-08-21 12:28:33 -07:00
platform efi/x86: Move 32-bit code into efi_32.c 2020-08-20 11:18:36 +02:00
power Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
purgatory Misc fixes and small updates all around the place: 2020-08-15 10:38:03 -07:00
ras treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
realmode Rebase locking/kcsan to locking/urgent 2020-06-11 20:02:46 +02:00
tools
um kbuild: remove cc-option test of -fno-stack-protector 2020-07-07 11:13:10 +09:00
video
xen xen: branch for v5.9-rc1b 2020-08-14 13:34:37 -07:00
.gitignore
Kbuild
Kconfig A set of posix CPU timer changes which allows to defer the heavy work of 2020-08-14 14:17:51 -07:00
Kconfig.assembler x86/delay: Introduce TPAUSE delay 2020-05-07 16:06:20 +02:00
Kconfig.cpu treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Kconfig.debug locking/lockdep: Fix TRACE_IRQFLAGS vs. NMIs 2020-07-27 15:13:29 +02:00
Makefile Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
Makefile_32.cpu
Makefile.um