Commit d45111e5 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

Pull x86 kvm fixes from Paolo Bonzini:
 "Many small fixes that accumulated while I was on vacation...

   - Fixup missed comments from the REMOVED_SPTE => FROZEN_SPTE rename

   - Ensure a root is successfully loaded when pre-faulting SPTEs

   - Grab kvm->srcu when handling KVM_SET_VCPU_EVENTS to guard against
     accessing memslots if toggling SMM happens to force a VM-Exit

   - Emulate MSR_{FS,GS}_BASE on SVM even though interception is always
     disabled, so that KVM does the right thing if KVM's emulator
     encounters {RD,WR}MSR

   - Explicitly clear BUS_LOCK_DETECT from KVM's caps on AMD, as KVM
     doesn't yet virtualize BUS_LOCK_DETECT on AMD

   - Cleanup the help message for CONFIG_KVM_AMD_SEV, and call out that
     KVM now supports SEV-SNP too

   - Specialize return value of
     KVM_CHECK_EXTENSION(KVM_CAP_READONLY_MEM), based on VM type

   - Remove unnecessary dependency on CONFIG_HIGH_RES_TIMERS

   - Note an RCU quiescent state on guest exit. This avoids a call to
     rcu_core() if there was a grace period request while guest was
     running"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: Remove HIGH_RES_TIMERS dependency
  kvm: Note an RCU quiescent state on guest exit
  KVM: x86: Only advertise KVM_CAP_READONLY_MEM when supported by VM
  KVM: SEV: Update KVM_AMD_SEV Kconfig entry and mention SEV-SNP
  KVM: SVM: Don't advertise Bus Lock Detect to guest if SVM support is missing
  KVM: SVM: fix emulation of msr reads/writes of MSR_FS_BASE and MSR_GS_BASE
  KVM: x86: Acquire kvm->srcu when handling KVM_SET_VCPU_EVENTS
  KVM: x86/mmu: Check that root is valid/loaded when pre-faulting SPTEs
  KVM: x86/mmu: Fixup comments missed by the REMOVED_SPTE=>FROZEN_SPTE rename
parents 788220ee 59cbd4ee

arch/x86/kvm/Kconfig

+4 −3
Original line number Diff line number Diff line
@@ -19,7 +19,6 @@ if VIRTUALIZATION 


config KVM

	tristate "Kernel-based Virtual Machine (KVM) support"

	depends on HIGH_RES_TIMERS

	depends on X86_LOCAL_APIC

	select KVM_COMMON

	select KVM_GENERIC_MMU_NOTIFIER
@@ -144,8 +143,10 @@ config KVM_AMD_SEV 
	select HAVE_KVM_ARCH_GMEM_PREPARE

	select HAVE_KVM_ARCH_GMEM_INVALIDATE

	help

	  Provides support for launching Encrypted VMs (SEV) and Encrypted VMs

	  with Encrypted State (SEV-ES) on AMD processors.

	  Provides support for launching encrypted VMs which use Secure

	  Encrypted Virtualization (SEV), Secure Encrypted Virtualization with

	  Encrypted State (SEV-ES), and Secure Encrypted Virtualization with

	  Secure Nested Paging (SEV-SNP) technologies on AMD processors.



config KVM_SMM

	bool "System Management Mode emulation"

arch/x86/kvm/mmu/mmu.c

+3 −1
Original line number Diff line number Diff line
@@ -4750,7 +4750,9 @@ long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu, 
	 * reload is efficient when called repeatedly, so we can do it on

	 * every iteration.

	 */

	kvm_mmu_reload(vcpu);

	r = kvm_mmu_reload(vcpu);

	if (r)

		return r;



	if (kvm_arch_has_private_mem(vcpu->kvm) &&

	    kvm_mem_is_private(vcpu->kvm, gpa_to_gfn(range->gpa)))

arch/x86/kvm/mmu/spte.c

+3 −3
Original line number Diff line number Diff line
@@ -391,9 +391,9 @@ void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 mmio_mask, u64 access_mask) 
		mmio_value = 0;



	/*

	 * The masked MMIO value must obviously match itself and a removed SPTE

	 * must not get a false positive.  Removed SPTEs and MMIO SPTEs should

	 * never collide as MMIO must set some RWX bits, and removed SPTEs must

	 * The masked MMIO value must obviously match itself and a frozen SPTE

	 * must not get a false positive.  Frozen SPTEs and MMIO SPTEs should

	 * never collide as MMIO must set some RWX bits, and frozen SPTEs must

	 * not set any RWX bits.

	 */

	if (WARN_ON((mmio_value & mmio_mask) != mmio_value) ||

arch/x86/kvm/mmu/spte.h

+1 −1
Original line number Diff line number Diff line
@@ -214,7 +214,7 @@ extern u64 __read_mostly shadow_nonpresent_or_rsvd_mask; 
 */

#define FROZEN_SPTE	(SHADOW_NONPRESENT_VALUE | 0x5a0ULL)



/* Removed SPTEs must not be misconstrued as shadow present PTEs. */

/* Frozen SPTEs must not be misconstrued as shadow present PTEs. */

static_assert(!(FROZEN_SPTE & SPTE_MMU_PRESENT_MASK));



static inline bool is_frozen_spte(u64 spte)

arch/x86/kvm/mmu/tdp_mmu.c

+4 −4
Original line number Diff line number Diff line
@@ -359,10 +359,10 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared) 
			/*

			 * Set the SPTE to a nonpresent value that other

			 * threads will not overwrite. If the SPTE was

			 * already marked as removed then another thread

			 * already marked as frozen then another thread

			 * handling a page fault could overwrite it, so

			 * set the SPTE until it is set from some other

			 * value to the removed SPTE value.

			 * value to the frozen SPTE value.

			 */

			for (;;) {

				old_spte = kvm_tdp_mmu_write_spte_atomic(sptep, FROZEN_SPTE);
@@ -536,8 +536,8 @@ static inline int __must_check __tdp_mmu_set_spte_atomic(struct tdp_iter *iter, 
	u64 *sptep = rcu_dereference(iter->sptep);



	/*

	 * The caller is responsible for ensuring the old SPTE is not a REMOVED

	 * SPTE.  KVM should never attempt to zap or manipulate a REMOVED SPTE,

	 * The caller is responsible for ensuring the old SPTE is not a FROZEN

	 * SPTE.  KVM should never attempt to zap or manipulate a FROZEN SPTE,

	 * and pre-checking before inserting a new SPTE is advantageous as it

	 * avoids unnecessary work.

	 */