Commit 3643a148 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by sanglipeng
Browse files

KVM: VMX: Introduce vmx_msr_bitmap_l01_changed() helper 

stable inclusion
from stable-v5.10.175
commit 685ed0a277f16881090891988b4d93257f8caf3c
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8711T

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=685ed0a277f16881090891988b4d93257f8caf3c



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

commit b84155c3 upstream.

In preparation to enabling 'Enlightened MSR Bitmap' feature for Hyper-V
guests move MSR bitmap update tracking to a dedicated helper.

Note: vmx_msr_bitmap_l01_changed() is called when MSR bitmap might be
updated. KVM doesn't check if the bit we're trying to set is already set
(or the bit it's trying to clear is already cleared). Such situations
should not be common and a few false positives should not be a problem.

No functional change intended.

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20211129094704.326635-3-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarAlexandru Matei <alexandru.matei@uipath.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarsanglipeng <sanglipeng1@jd.com>
parent 1b6b715c

arch/x86/kvm/vmx/vmx.c

+13 −4
Original line number Diff line number Diff line
@@ -3962,6 +3962,17 @@ static void vmx_set_msr_bitmap_write(ulong *msr_bitmap, u32 msr) 
		__set_bit(msr & 0x1fff, msr_bitmap + 0xc00 / f);

}



static void vmx_msr_bitmap_l01_changed(struct vcpu_vmx *vmx)

{

	/*

	 * When KVM is a nested hypervisor on top of Hyper-V and uses

	 * 'Enlightened MSR Bitmap' feature L0 needs to know that MSR

	 * bitmap has changed.

	 */

	if (static_branch_unlikely(&enable_evmcs))

		evmcs_touch_msr_bitmap();

}



static __always_inline void vmx_disable_intercept_for_msr(struct kvm_vcpu *vcpu,

							  u32 msr, int type)

{
@@ -3971,8 +3982,7 @@ static __always_inline void vmx_disable_intercept_for_msr(struct kvm_vcpu *vcpu, 
	if (!cpu_has_vmx_msr_bitmap())

		return;



	if (static_branch_unlikely(&enable_evmcs))

		evmcs_touch_msr_bitmap();

	vmx_msr_bitmap_l01_changed(vmx);



	/*

	 * Mark the desired intercept state in shadow bitmap, this is needed
@@ -4017,8 +4027,7 @@ static __always_inline void vmx_enable_intercept_for_msr(struct kvm_vcpu *vcpu, 
	if (!cpu_has_vmx_msr_bitmap())

		return;



	if (static_branch_unlikely(&enable_evmcs))

		evmcs_touch_msr_bitmap();

	vmx_msr_bitmap_l01_changed(vmx);



	/*

	 * Mark the desired intercept state in shadow bitmap, this is needed