linux_dsm_epyc7002/arch/x86
Paolo Bonzini 0c899c25d7 KVM: x86: do not attempt TSC synchronization on guest writes
KVM special-cases writes to MSR_IA32_TSC so that all CPUs have
the same base for the TSC.  This logic is complicated, and we
do not want it to have any effect once the VM is started.

In particular, if any guest started to synchronize its TSCs
with writes to MSR_IA32_TSC rather than MSR_IA32_TSC_ADJUST,
the additional effect of kvm_write_tsc code would be uncharted
territory.

Therefore, this patch makes writes to MSR_IA32_TSC behave
essentially the same as writes to MSR_IA32_TSC_ADJUST when
they come from the guest.  A new selftest (which passes
both before and after the patch) checks the current semantics
of writes to MSR_IA32_TSC and MSR_IA32_TSC_ADJUST originating
from both the host and the guest.

Upcoming work to remove the special side effects
of host-initiated writes to MSR_IA32_TSC and MSR_IA32_TSC_ADJUST
will be able to build onto this test, adjusting the host side
to use the new APIs and achieve the same effect.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-09-28 07:59:52 -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: rename KVM_REQ_GET_VMCS12_PAGES 2020-09-28 07:58:49 -04:00
kernel cpuidle-haltpoll: fix error comments in arch_haltpoll_disable 2020-09-28 07:57:28 -04:00
kvm KVM: x86: do not attempt TSC synchronization on guest writes 2020-09-28 07:59:52 -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, fakenuma: Fix invalid starting node ID 2020-09-04 08:56:13 +02:00
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