linux-kernel - [PATCH 3.16 019/136] KVM: nVMX: set IDTR and GDTR limits when loading L1 host state

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Message-ID: <lsq.1518323471.292935615@decadent.org.uk>
Date:   Sun, 11 Feb 2018 04:31:11 +0000
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, "Paolo Bonzini" <pbonzini@...hat.com>,
        "Ladi Prosek" <lprosek@...hat.com>
Subject: [PATCH 3.16 019/136] KVM: nVMX: set IDTR and GDTR limits when
 loading L1 host state

3.16.54-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Ladi Prosek <lprosek@...hat.com>

commit 21f2d551183847bc7fbe8d866151d00cdad18752 upstream.

Intel SDM 27.5.2 Loading Host Segment and Descriptor-Table Registers:

"The GDTR and IDTR limits are each set to FFFFH."

Signed-off-by: Ladi Prosek <lprosek@...hat.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 arch/x86/kvm/vmx.c | 2 ++
 1 file changed, 2 insertions(+)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8695,6 +8695,8 @@ static void load_vmcs12_host_state(struc
 	vmcs_writel(GUEST_SYSENTER_EIP, vmcs12->host_ia32_sysenter_eip);
 	vmcs_writel(GUEST_IDTR_BASE, vmcs12->host_idtr_base);
 	vmcs_writel(GUEST_GDTR_BASE, vmcs12->host_gdtr_base);
+	vmcs_write32(GUEST_IDTR_LIMIT, 0xFFFF);
+	vmcs_write32(GUEST_GDTR_LIMIT, 0xFFFF);
 
 	/* If not VM_EXIT_CLEAR_BNDCFGS, the L2 value propagates to L1.  */
 	if (vmcs12->vm_exit_controls & VM_EXIT_CLEAR_BNDCFGS)