Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
 "More fixes for ARM and x86"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: LAPIC: Advancing the timer expiration on guest initiated write
  KVM: x86/mmu: Skip !MMU-present SPTEs when removing SP in exclusive mode
  KVM: kvmclock: Fix vCPUs > 64 can't be online/hotpluged
  kvm: x86: annotate RCU pointers
  KVM: arm64: Fix exclusive limit for IPA size
  KVM: arm64: Reject VM creation when the default IPA size is unsupported
  KVM: arm64: Ensure I-cache isolation between vcpus of a same VM
  KVM: arm64: Don't use cbz/adr with external symbols
  KVM: arm64: Fix range alignment when walking page tables
  KVM: arm64: Workaround firmware wrongly advertising GICv2-on-v3 compatibility
  KVM: arm64: Rename __vgic_v3_get_ich_vtr_el2() to __vgic_v3_get_gic_config()
  KVM: arm64: Don't access PMSELR_EL0/PMUSERENR_EL0 when no PMU is available
  KVM: arm64: Turn kvm_arm_support_pmu_v3() into a static key
  KVM: arm64: Fix nVHE hyp panic host context restore
  KVM: arm64: Avoid corrupting vCPU context register in guest exit
  KVM: arm64: nvhe: Save the SPE context early
  kvm: x86: use NULL instead of using plain integer as pointer
  KVM: SVM: Connect 'npt' module param to KVM's internal 'npt_enabled'
  KVM: x86: Ensure deadline timer has truly expired before posting its IRQ

1 files changed, 13 insertions, 12 deletions

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index baee91c1e936..58a45bb139f8 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -115,13 +115,6 @@ static const struct svm_direct_access_msrs {
 	{ .index = MSR_INVALID,				.always = false },
 };
 
-/* enable NPT for AMD64 and X86 with PAE */
-#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
-bool npt_enabled = true;
-#else
-bool npt_enabled;
-#endif
-
 /*
  * These 2 parameters are used to config the controls for Pause-Loop Exiting:
  * pause_filter_count: On processors that support Pause filtering(indicated
@@ -170,9 +163,12 @@ module_param(pause_filter_count_shrink, ushort, 0444);
 static unsigned short pause_filter_count_max = KVM_SVM_DEFAULT_PLE_WINDOW_MAX;
 module_param(pause_filter_count_max, ushort, 0444);
 
-/* allow nested paging (virtualized MMU) for all guests */
-static int npt = true;
-module_param(npt, int, S_IRUGO);
+/*
+ * Use nested page tables by default.  Note, NPT may get forced off by
+ * svm_hardware_setup() if it's unsupported by hardware or the host kernel.
+ */
+bool npt_enabled = true;
+module_param_named(npt, npt_enabled, bool, 0444);
 
 /* allow nested virtualization in KVM/SVM */
 static int nested = true;
@@ -988,10 +984,15 @@ static __init int svm_hardware_setup(void)
 			goto err;
 	}
 
-	if (!boot_cpu_has(X86_FEATURE_NPT))
+	/*
+	 * KVM's MMU doesn't support using 2-level paging for itself, and thus
+	 * NPT isn't supported if the host is using 2-level paging since host
+	 * CR4 is unchanged on VMRUN.
+	 */
+	if (!IS_ENABLED(CONFIG_X86_64) && !IS_ENABLED(CONFIG_X86_PAE))
 		npt_enabled = false;
 
-	if (npt_enabled && !npt)
+	if (!boot_cpu_has(X86_FEATURE_NPT))
 		npt_enabled = false;
 
 	kvm_configure_mmu(npt_enabled, get_max_npt_level(), PG_LEVEL_1G);