[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <1510584031-36240-1-git-send-email-pbonzini@redhat.com>
Date: Mon, 13 Nov 2017 15:40:26 +0100
From: Paolo Bonzini <pbonzini@...hat.com>
To: linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc: rkrcmar@...hat.com
Subject: [PATCH for-4.15 0/5] KVM: (almost) emulate UMIP on current processors
The User-Mode Instruction Prevention feature present in recent Intel
processor prevents a group of instructions (sgdt, sidt, sldt, smsw, and
str) from being executed with CPL > 0. Otherwise, a general protection
fault is issued.
Add support for UMIP in virtual machines, and also allow emulation of
UMIP on older processors by enabling descriptor-table vmexits. This
emulation is not perfect, because SMSW cannot be trapped. However,
this is not an issue in practice because Linux is _also_ emulating SMSW
instructions on behalf of the program that executes them, because some
16-bit programs expect to use SMSW to detect vm86 mode.
Paolo
Paolo Bonzini (5):
KVM: vmx: use X86_CR4_UMIP and X86_FEATURE_UMIP
KVM: x86: add support for UMIP
KVM: x86: emulate sldt and str
KVM: x86: add support for emulating UMIP
KVM: vmx: add support for emulating UMIP
arch/x86/include/asm/kvm_host.h | 3 ++-
arch/x86/kvm/cpuid.c | 6 ++++--
arch/x86/kvm/emulate.c | 40 ++++++++++++++++++++++++++++++++++------
arch/x86/kvm/svm.c | 6 ++++++
arch/x86/kvm/vmx.c | 36 +++++++++++++++++++++++++++++++++---
arch/x86/kvm/x86.c | 3 +++
6 files changed, 82 insertions(+), 12 deletions(-)
--
1.8.3.1
Powered by blists - more mailing lists