From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?q?Adalber=20Laz=C4=83r?= Subject: [RFC PATCH v4 16/18] kvm: x86: hook in kvmi_msr_event() Date: Mon, 18 Dec 2017 21:06:40 +0200 Message-ID: <20171218190642.7790-17-alazar@bitdefender.com> References: <20171218190642.7790-1-alazar@bitdefender.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: linux-mm@kvack.org, Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Xiao Guangrong , =?UTF-8?q?Mihai=20Don=C8=9Bu?= , Adalbert Lazar To: kvm@vger.kernel.org Return-path: In-Reply-To: <20171218190642.7790-1-alazar@bitdefender.com> Sender: owner-linux-mm@kvack.org List-Id: kvm.vger.kernel.org From: Adalbert Lazar Inform the guest introspection tool that an MSR is going to be changed. The kvmi_msr_event() function will check a bitmap of MSR-s of interest (configured via a KVMI_CONTROL_EVENTS(KVMI_MSR_CONTROL) request) and, if the new value differs from the previous one, it will generate a notification. The introspection tool can respond by allowing the guest to continue with normal execution or by discarding the change. This is meant to prevent malicious changes to MSR-s such as MSR_IA32_SYSENTER_EIP. Signed-off-by: Mihai Donțu --- arch/x86/kvm/x86.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 284bb4c740fa..271028ccbeca 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1111,6 +1111,9 @@ EXPORT_SYMBOL_GPL(kvm_enable_efer_bits); */ int kvm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) { + if (!kvmi_msr_event(vcpu, msr)) + return 1; + switch (msr->index) { case MSR_FS_BASE: case MSR_GS_BASE: -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org