linux_dsm_epyc7002/arch
Sean Christopherson 361209e054 KVM: Explicitly define the "memslot update in-progress" bit
KVM uses bit 0 of the memslots generation as an "update in-progress"
flag, which is used by x86 to prevent caching MMIO access while the
memslots are changing.  Although the intended behavior is flag-like,
e.g. MMIO sptes intentionally drop the in-progress bit so as to avoid
caching data from in-flux memslots, the implementation oftentimes treats
the bit as part of the generation number itself, e.g. incrementing the
generation increments twice, once to set the flag and once to clear it.

Prior to commit 4bd518f159 ("KVM: use separate generations for
each address space"), incorporating the "update in-progress" bit into
the generation number largely made sense, e.g. "real" generations are
even, "bogus" generations are odd, most code doesn't need to be aware of
the bit, etc...

Now that unique memslots generation numbers are assigned to each address
space, stealthing the in-progress status into the generation number
results in a wide variety of subtle code, e.g. kvm_create_vm() jumps
over bit 0 when initializing the memslots generation without any hint as
to why.

Explicitly define the flag and convert as much code as possible (which
isn't much) to actually treat it like a flag.  This paves the way for
eventually using a different bit for "update in-progress" so that it can
be a flag in truth instead of a awkward extension to the generation
number.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-20 22:48:34 +01:00
..
alpha
arc
arm xen: fixes for 5.0-rc6 2019-02-09 09:44:08 -08:00
arm64 ARM: SoC fixes for linux-5.0 2019-02-08 16:23:41 -08:00
c6x arch: unexport asm/shmparam.h for all architectures 2019-02-01 15:46:22 -08:00
csky
h8300 arch: unexport asm/shmparam.h for all architectures 2019-02-01 15:46:22 -08:00
hexagon arch: unexport asm/shmparam.h for all architectures 2019-02-01 15:46:22 -08:00
ia64
m68k for-linus-20190209 2019-02-09 10:26:09 -08:00
microblaze arch: unexport asm/shmparam.h for all architectures 2019-02-01 15:46:22 -08:00
mips KVM: Call kvm_arch_memslots_updated() before updating memslots 2019-02-20 22:48:32 +01:00
nds32
nios2
openrisc arch: unexport asm/shmparam.h for all architectures 2019-02-01 15:46:22 -08:00
parisc
powerpc KVM: Call kvm_arch_memslots_updated() before updating memslots 2019-02-20 22:48:32 +01:00
riscv
s390 KVM: Call kvm_arch_memslots_updated() before updating memslots 2019-02-20 22:48:32 +01:00
sh
sparc
um
unicore32 arch: unexport asm/shmparam.h for all architectures 2019-02-01 15:46:22 -08:00
x86 KVM: Explicitly define the "memslot update in-progress" bit 2019-02-20 22:48:34 +01:00
xtensa xtensa: SMP: limit number of possible CPUs by NR_CPUS 2019-01-27 10:04:30 -08:00
.gitignore
Kconfig