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FAILED: patch "[PATCH] KVM: nVMX: Don't propagate vmcs12's PERF_GLOBAL_CTRL settings" failed to apply to 4.14-stable tree

PATCH [email protected] 1 participant 1 message Oct 16, 2022

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The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Possible dependencies:

def9d705c05e ("KVM: nVMX: Don't propagate vmcs12's PERF_GLOBAL_CTRL settings to vmcs02") 389ab25216c9 ("KVM: nVMX: Pull KVM L0's desired controls directly from vmcs01")
d041b5ea9335 ("KVM: nVMX: Enable nested TSC scaling")
5e3d394fdd9e ("KVM: VMX: Fix the spelling of CPU_BASED_USE_TSC_OFFSETTING")
4e2a0bc56ad1 ("KVM: VMX: Rename NMI_PENDING to NMI_WINDOW")
9dadc2f918df ("KVM: VMX: Rename INTERRUPT_PENDING to INTERRUPT_WINDOW")
4289d2728664 ("KVM: retpolines: x86: eliminate retpoline from vmx.c exit handlers") f399e60c45f6 ("KVM: x86: optimize more exit handlers in vmx.c")
b7ad61084842 ("tools headers kvm: Sync kvm headers with the kernel sources")
4a53d99dd0c2 ("KVM: VMX: Introduce exit reason for receiving INIT signal on guest-mode") 5497b95567c1 ("KVM: nVMX: add tracepoint for failed nested VM-Enter")
1edce0a9eb23 ("KVM: x86: Add kvm_emulate_{rd,wr}msr() to consolidate VXM/SVM code") f20935d85a23 ("KVM: x86: Refactor up kvm_{g,s}et_msr() to simplify callers")
32d1d15c52c1 ("Merge tag 'kvmarm-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From def9d705c05eab3fdedeb10ad67907513b12038e Mon Sep 17 00:00:00 2001
From: Sean Christopherson <[email protected]>
Date: Tue, 30 Aug 2022 15:37:21 +0200
Subject: [PATCH] KVM: nVMX: Don't propagate vmcs12's PERF_GLOBAL_CTRL settings
to vmcs02

Don't propagate vmcs12's VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL to vmcs02. KVM doesn't disallow L1 from using VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL even when KVM itself doesn't use the control, e.g. due to the various CPU errata that where the MSR can be corrupted on VM-Exit.

Preserve KVM's (vmcs01) setting to hopefully avoid having to toggle the bit in vmcs02 at a later point. E.g. if KVM is loading PERF_GLOBAL_CTRL when running L1, then odds are good KVM will also load the MSR when running L2.

Fixes 8bf00a529967 ("KVM: VMX: add support for switching of PERF_GLOBAL_CTRL")
arch/x86/kvm/vmx/nested.c +6 -1
index 1743319015b7..400e015afa64 100644
@@ -2359,9 +2359,14 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct loaded_vmcs *vmcs0
 	 * are emulated by vmx_set_efer() in prepare_vmcs02(), but speculate
 	 * on the related bits (if supported by the CPU) in the hope that
 	 * we can avoid VMWrites during vmx_set_efer().
+	 *
+	 * Similarly, take vmcs01's PERF_GLOBAL_CTRL in the hope that if KVM is
+	 * loading PERF_GLOBAL_CTRL via the VMCS for L1, then KVM will want to
+	 * do the same for L2.
 	 */
 	exec_control = __vm_entry_controls_get(vmcs01);
-	exec_control |= vmcs12->vm_entry_controls;
+	exec_control |= (vmcs12->vm_entry_controls &
+			 ~VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL);
 	exec_control &= ~(VM_ENTRY_IA32E_MODE | VM_ENTRY_LOAD_IA32_EFER);
 	if (cpu_has_load_ia32_efer()) {
 		if (guest_efer & EFER_LMA)