Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "The main changes are the PCID fixes from Andy, but there's also two
  hyperv fixes and two paravirt updates"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/hyper-v: Remove duplicated HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED definition
  x86/hyper-V: Allocate the IDT entry early in boot
  paravirt: Switch maintainer
  x86/paravirt: Remove no longer used paravirt functions
  x86/mm/64: Initialize CR4.PCIDE early
  x86/hibernate/64: Mask off CR3's PCID bits in the saved CR3
  x86/mm: Get rid of VM_BUG_ON in switch_tlb_irqs_off()

18 files changed, 105 insertions, 148 deletions

diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index 1a2ba368da39..9d0e13738ed3 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -121,7 +121,6 @@ static inline int desc_empty(const void *ptr)
 #define load_ldt(ldt)				asm volatile("lldt %0"::"m" (ldt))
 
 #define store_gdt(dtr)				native_store_gdt(dtr)
-#define store_idt(dtr)				native_store_idt(dtr)
 #define store_tr(tr)				(tr = native_store_tr())
 
 #define load_TLS(t, cpu)			native_load_tls(t, cpu)
@@ -228,7 +227,7 @@ static inline void native_store_gdt(struct desc_ptr *dtr)
 	asm volatile("sgdt %0":"=m" (*dtr));
 }
 
-static inline void native_store_idt(struct desc_ptr *dtr)
+static inline void store_idt(struct desc_ptr *dtr)
 {
 	asm volatile("sidt %0":"=m" (*dtr));
 }
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index c25dd22f7c70..12deec722cf0 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -71,11 +71,6 @@ static inline void write_cr3(unsigned long x)
 	PVOP_VCALL1(pv_mmu_ops.write_cr3, x);
 }
 
-static inline unsigned long __read_cr4(void)
-{
-	return PVOP_CALL0(unsigned long, pv_cpu_ops.read_cr4);
-}
-
 static inline void __write_cr4(unsigned long x)
 {
 	PVOP_VCALL1(pv_cpu_ops.write_cr4, x);
@@ -228,10 +223,6 @@ static inline void set_ldt(const void *addr, unsigned entries)
 {
 	PVOP_VCALL2(pv_cpu_ops.set_ldt, addr, entries);
 }
-static inline void store_idt(struct desc_ptr *dtr)
-{
-	PVOP_VCALL1(pv_cpu_ops.store_idt, dtr);
-}
 static inline unsigned long paravirt_store_tr(void)
 {
 	return PVOP_CALL0(unsigned long, pv_cpu_ops.store_tr);
@@ -365,12 +356,6 @@ static inline void paravirt_release_p4d(unsigned long pfn)
 	PVOP_VCALL1(pv_mmu_ops.release_p4d, pfn);
 }
 
-static inline void pte_update(struct mm_struct *mm, unsigned long addr,
-			      pte_t *ptep)
-{
-	PVOP_VCALL3(pv_mmu_ops.pte_update, mm, addr, ptep);
-}
-
 static inline pte_t __pte(pteval_t val)
 {
 	pteval_t ret;
@@ -472,28 +457,6 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 		PVOP_VCALL4(pv_mmu_ops.set_pte_at, mm, addr, ptep, pte.pte);
 }
 
-static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
-			      pmd_t *pmdp, pmd_t pmd)
-{
-	if (sizeof(pmdval_t) > sizeof(long))
-		/* 5 arg words */
-		pv_mmu_ops.set_pmd_at(mm, addr, pmdp, pmd);
-	else
-		PVOP_VCALL4(pv_mmu_ops.set_pmd_at, mm, addr, pmdp,
-			    native_pmd_val(pmd));
-}
-
-static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
-			      pud_t *pudp, pud_t pud)
-{
-	if (sizeof(pudval_t) > sizeof(long))
-		/* 5 arg words */
-		pv_mmu_ops.set_pud_at(mm, addr, pudp, pud);
-	else
-		PVOP_VCALL4(pv_mmu_ops.set_pud_at, mm, addr, pudp,
-			    native_pud_val(pud));
-}
-
 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 {
 	pmdval_t val = native_pmd_val(pmd);
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index 6b64fc6367f2..42873edd9f9d 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -107,7 +107,6 @@ struct pv_cpu_ops {
 	unsigned long (*read_cr0)(void);
 	void (*write_cr0)(unsigned long);
 
-	unsigned long (*read_cr4)(void);
 	void (*write_cr4)(unsigned long);
 
 #ifdef CONFIG_X86_64
@@ -119,8 +118,6 @@ struct pv_cpu_ops {
 	void (*load_tr_desc)(void);
 	void (*load_gdt)(const struct desc_ptr *);
 	void (*load_idt)(const struct desc_ptr *);
-	/* store_gdt has been removed. */
-	void (*store_idt)(struct desc_ptr *);
 	void (*set_ldt)(const void *desc, unsigned entries);
 	unsigned long (*store_tr)(void);
 	void (*load_tls)(struct thread_struct *t, unsigned int cpu);
@@ -245,12 +242,6 @@ struct pv_mmu_ops {
 	void (*set_pte_at)(struct mm_struct *mm, unsigned long addr,
 			   pte_t *ptep, pte_t pteval);
 	void (*set_pmd)(pmd_t *pmdp, pmd_t pmdval);
-	void (*set_pmd_at)(struct mm_struct *mm, unsigned long addr,
-			   pmd_t *pmdp, pmd_t pmdval);
-	void (*set_pud_at)(struct mm_struct *mm, unsigned long addr,
-			   pud_t *pudp, pud_t pudval);
-	void (*pte_update)(struct mm_struct *mm, unsigned long addr,
-			   pte_t *ptep);
 
 	pte_t (*ptep_modify_prot_start)(struct mm_struct *mm, unsigned long addr,
 					pte_t *ptep);
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 5b4c44d419c5..b714934512b3 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -55,8 +55,6 @@ extern pmdval_t early_pmd_flags;
 #else  /* !CONFIG_PARAVIRT */
 #define set_pte(ptep, pte)		native_set_pte(ptep, pte)
 #define set_pte_at(mm, addr, ptep, pte)	native_set_pte_at(mm, addr, ptep, pte)
-#define set_pmd_at(mm, addr, pmdp, pmd)	native_set_pmd_at(mm, addr, pmdp, pmd)
-#define set_pud_at(mm, addr, pudp, pud)	native_set_pud_at(mm, addr, pudp, pud)
 
 #define set_pte_atomic(ptep, pte)					\
 	native_set_pte_atomic(ptep, pte)
@@ -87,8 +85,6 @@ extern pmdval_t early_pmd_flags;
 #define pte_clear(mm, addr, ptep)	native_pte_clear(mm, addr, ptep)
 #define pmd_clear(pmd)			native_pmd_clear(pmd)
 
-#define pte_update(mm, addr, ptep)              do { } while (0)
-
 #define pgd_val(x)	native_pgd_val(x)
 #define __pgd(x)	native_make_pgd(x)
 
@@ -979,31 +975,18 @@ static inline void native_set_pte_at(struct mm_struct *mm, unsigned long addr,
 	native_set_pte(ptep, pte);
 }
 
-static inline void native_set_pmd_at(struct mm_struct *mm, unsigned long addr,
-				     pmd_t *pmdp , pmd_t pmd)
+static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
+			      pmd_t *pmdp, pmd_t pmd)
 {
 	native_set_pmd(pmdp, pmd);
 }
 
-static inline void native_set_pud_at(struct mm_struct *mm, unsigned long addr,
-				     pud_t *pudp, pud_t pud)
+static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
+			      pud_t *pudp, pud_t pud)
 {
 	native_set_pud(pudp, pud);
 }
 
-#ifndef CONFIG_PARAVIRT
-/*
- * Rules for using pte_update - it must be called after any PTE update which
- * has not been done using the set_pte / clear_pte interfaces.  It is used by
- * shadow mode hypervisors to resynchronize the shadow page tables.  Kernel PTE
- * updates should either be sets, clears, or set_pte_atomic for P->P
- * transitions, which means this hook should only be called for user PTEs.
- * This hook implies a P->P protection or access change has taken place, which
- * requires a subsequent TLB flush.
- */
-#define pte_update(mm, addr, ptep)		do { } while (0)
-#endif
-
 /*
  * We only update the dirty/accessed state if we set
  * the dirty bit by hand in the kernel, since the hardware
@@ -1031,7 +1014,6 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 				       pte_t *ptep)
 {
 	pte_t pte = native_ptep_get_and_clear(ptep);
-	pte_update(mm, addr, ptep);
 	return pte;
 }
 
@@ -1058,7 +1040,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm,
 				      unsigned long addr, pte_t *ptep)
 {
 	clear_bit(_PAGE_BIT_RW, (unsigned long *)&ptep->pte);
-	pte_update(mm, addr, ptep);
 }
 
 #define flush_tlb_fix_spurious_fault(vma, address) do { } while (0)
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index 9efaabf5b54b..a24dfcf79f4a 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -135,6 +135,11 @@ static inline void native_wbinvd(void)
 
 extern asmlinkage void native_load_gs_index(unsigned);
 
+static inline unsigned long __read_cr4(void)
+{
+	return native_read_cr4();
+}
+
 #ifdef CONFIG_PARAVIRT
 #include <asm/paravirt.h>
 #else
@@ -173,11 +178,6 @@ static inline void write_cr3(unsigned long x)
 	native_write_cr3(x);
 }
 
-static inline unsigned long __read_cr4(void)
-{
-	return native_read_cr4();
-}
-
 static inline void __write_cr4(unsigned long x)
 {
 	native_write_cr4(x);
diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
index 7032f4d8dff3..f65d12504e80 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -153,12 +153,6 @@
 #define HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED	(1 << 11)
 
 /*
- * HV_VP_SET available
- */
-#define HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED	(1 << 11)
-
-
-/*
  * Crash notification flag.
  */
 #define HV_CRASH_CTL_CRASH_NOTIFY (1ULL << 63)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index fb1d3358a4af..775f10100d7f 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -169,21 +169,21 @@ static int __init x86_mpx_setup(char *s)
 __setup("nompx", x86_mpx_setup);
 
 #ifdef CONFIG_X86_64
-static int __init x86_pcid_setup(char *s)
+static int __init x86_nopcid_setup(char *s)
 {
-	/* require an exact match without trailing characters */
-	if (strlen(s))
-		return 0;
+	/* nopcid doesn't accept parameters */
+	if (s)
+		return -EINVAL;
 
 	/* do not emit a message if the feature is not present */
 	if (!boot_cpu_has(X86_FEATURE_PCID))
-		return 1;
+		return 0;
 
 	setup_clear_cpu_cap(X86_FEATURE_PCID);
 	pr_info("nopcid: PCID feature disabled\n");
-	return 1;
+	return 0;
 }
-__setup("nopcid", x86_pcid_setup);
+early_param("nopcid", x86_nopcid_setup);
 #endif
 
 static int __init x86_noinvpcid_setup(char *s)
@@ -329,38 +329,6 @@ static __always_inline void setup_smap(struct cpuinfo_x86 *c)
 	}
 }
 
-static void setup_pcid(struct cpuinfo_x86 *c)
-{
-	if (cpu_has(c, X86_FEATURE_PCID)) {
-		if (cpu_has(c, X86_FEATURE_PGE)) {
-			/*
-			 * We'd like to use cr4_set_bits_and_update_boot(),
-			 * but we can't.  CR4.PCIDE is special and can only
-			 * be set in long mode, and the early CPU init code
-			 * doesn't know this and would try to restore CR4.PCIDE
-			 * prior to entering long mode.
-			 *
-			 * Instead, we rely on the fact that hotplug, resume,
-			 * etc all fully restore CR4 before they write anything
-			 * that could have nonzero PCID bits to CR3.  CR4.PCIDE
-			 * has no effect on the page tables themselves, so we
-			 * don't need it to be restored early.
-			 */
-			cr4_set_bits(X86_CR4_PCIDE);
-		} else {
-			/*
-			 * flush_tlb_all(), as currently implemented, won't
-			 * work if PCID is on but PGE is not.  Since that
-			 * combination doesn't exist on real hardware, there's
-			 * no reason to try to fully support it, but it's
-			 * polite to avoid corrupting data if we're on
-			 * an improperly configured VM.
-			 */
-			clear_cpu_cap(c, X86_FEATURE_PCID);
-		}
-	}
-}
-
 /*
  * Protection Keys are not available in 32-bit mode.
  */
@@ -1175,9 +1143,6 @@ static void identify_cpu(struct cpuinfo_x86 *c)
 	setup_smep(c);
 	setup_smap(c);
 
-	/* Set up PCID */
-	setup_pcid(c);
-
 	/*
 	 * The vendor-specific functions might have changed features.
 	 * Now we do "generic changes."
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 3b3f713e15e5..236324e83a3a 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -59,8 +59,6 @@ void hyperv_vector_handler(struct pt_regs *regs)
 void hv_setup_vmbus_irq(void (*handler)(void))
 {
 	vmbus_handler = handler;
-	/* Setup the IDT for hypervisor callback */
-	alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector);
 }
 
 void hv_remove_vmbus_irq(void)
@@ -251,6 +249,8 @@ static void __init ms_hyperv_init_platform(void)
 	 */
 	x86_platform.apic_post_init = hyperv_init;
 	hyperv_setup_mmu_ops();
+	/* Setup the IDT for hypervisor callback */
+	alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector);
 #endif
 }
 
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index a14df9eecfed..19a3e8f961c7 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -327,7 +327,6 @@ __visible struct pv_cpu_ops pv_cpu_ops = {
 	.set_debugreg = native_set_debugreg,
 	.read_cr0 = native_read_cr0,
 	.write_cr0 = native_write_cr0,
-	.read_cr4 = native_read_cr4,
 	.write_cr4 = native_write_cr4,
 #ifdef CONFIG_X86_64
 	.read_cr8 = native_read_cr8,
@@ -343,7 +342,6 @@ __visible struct pv_cpu_ops pv_cpu_ops = {
 	.set_ldt = native_set_ldt,
 	.load_gdt = native_load_gdt,
 	.load_idt = native_load_idt,
-	.store_idt = native_store_idt,
 	.store_tr = native_store_tr,
 	.load_tls = native_load_tls,
 #ifdef CONFIG_X86_64
@@ -411,8 +409,6 @@ struct pv_mmu_ops pv_mmu_ops __ro_after_init = {
 	.set_pte = native_set_pte,
 	.set_pte_at = native_set_pte_at,
 	.set_pmd = native_set_pmd,
-	.set_pmd_at = native_set_pmd_at,
-	.pte_update = paravirt_nop,
 
 	.ptep_modify_prot_start = __ptep_modify_prot_start,
 	.ptep_modify_prot_commit = __ptep_modify_prot_commit,
@@ -424,7 +420,6 @@ struct pv_mmu_ops pv_mmu_ops __ro_after_init = {
 	.pmd_clear = native_pmd_clear,
 #endif
 	.set_pud = native_set_pud,
-	.set_pud_at = native_set_pud_at,
 
 	.pmd_val = PTE_IDENT,
 	.make_pmd = PTE_IDENT,
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index d84afb0a322d..0957dd73d127 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1178,8 +1178,11 @@ void __init setup_arch(char **cmdline_p)
 	 * with the current CR4 value.  This may not be necessary, but
 	 * auditing all the early-boot CR4 manipulation would be needed to
 	 * rule it out.
+	 *
+	 * Mask off features that don't work outside long mode (just
+	 * PCIDE for now).
 	 */
-	mmu_cr4_features = __read_cr4();
+	mmu_cr4_features = __read_cr4() & ~X86_CR4_PCIDE;
 
 	memblock_set_current_limit(get_max_mapped());
 
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index cd6622c3204e..0854ff169274 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -226,10 +226,12 @@ static int enable_start_cpu0;
 static void notrace start_secondary(void *unused)
 {
 	/*
-	 * Don't put *anything* before cpu_init(), SMP booting is too
-	 * fragile that we want to limit the things done here to the
-	 * most necessary things.
+	 * Don't put *anything* except direct CPU state initialization
+	 * before cpu_init(), SMP booting is too fragile that we want to
+	 * limit the things done here to the most necessary things.
 	 */
+	if (boot_cpu_has(X86_FEATURE_PCID))
+		__write_cr4(__read_cr4() | X86_CR4_PCIDE);
 	cpu_init();
 	x86_cpuinit.early_percpu_clock_init();
 	preempt_disable();
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 4253adef9044..699704d4bc9e 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5192,7 +5192,7 @@ static void vmx_set_constant_host_state(struct vcpu_vmx *vmx)
 	vmcs_write16(HOST_SS_SELECTOR, __KERNEL_DS);  /* 22.2.4 */
 	vmcs_write16(HOST_TR_SELECTOR, GDT_ENTRY_TSS*8);  /* 22.2.4 */
 
-	native_store_idt(&dt);
+	store_idt(&dt);
 	vmcs_writel(HOST_IDTR_BASE, dt.address);   /* 22.2.4 */
 	vmx->host_idt_base = dt.address;
 
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 7777ccc0e9f9..af5c1ed21d43 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -19,6 +19,7 @@
 #include <asm/microcode.h>
 #include <asm/kaslr.h>
 #include <asm/hypervisor.h>
+#include <asm/cpufeature.h>
 
 /*
  * We need to define the tracepoints somewhere, and tlb.c
@@ -193,6 +194,38 @@ static void __init probe_page_size_mask(void)
 	}
 }
 
+static void setup_pcid(void)
+{
+#ifdef CONFIG_X86_64
+	if (boot_cpu_has(X86_FEATURE_PCID)) {
+		if (boot_cpu_has(X86_FEATURE_PGE)) {
+			/*
+			 * This can't be cr4_set_bits_and_update_boot() --
+			 * the trampoline code can't handle CR4.PCIDE and
+			 * it wouldn't do any good anyway.  Despite the name,
+			 * cr4_set_bits_and_update_boot() doesn't actually
+			 * cause the bits in question to remain set all the
+			 * way through the secondary boot asm.
+			 *
+			 * Instead, we brute-force it and set CR4.PCIDE
+			 * manually in start_secondary().
+			 */
+			cr4_set_bits(X86_CR4_PCIDE);
+		} else {
+			/*
+			 * flush_tlb_all(), as currently implemented, won't
+			 * work if PCID is on but PGE is not.  Since that
+			 * combination doesn't exist on real hardware, there's
+			 * no reason to try to fully support it, but it's
+			 * polite to avoid corrupting data if we're on
+			 * an improperly configured VM.
+			 */
+			setup_clear_cpu_cap(X86_FEATURE_PCID);
+		}
+	}
+#endif
+}
+
 #ifdef CONFIG_X86_32
 #define NR_RANGE_MR 3
 #else /* CONFIG_X86_64 */
@@ -592,6 +625,7 @@ void __init init_mem_mapping(void)
 	unsigned long end;
 
 	probe_page_size_mask();
+	setup_pcid();
 
 #ifdef CONFIG_X86_64
 	end = max_pfn << PAGE_SHIFT;
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 218834a3e9ad..b372f3442bbf 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -426,10 +426,8 @@ int ptep_set_access_flags(struct vm_area_struct *vma,
 {
 	int changed = !pte_same(*ptep, entry);
 
-	if (changed && dirty) {
+	if (changed && dirty)
 		*ptep = entry;
-		pte_update(vma->vm_mm, address, ptep);
-	}
 
 	return changed;
 }
@@ -486,9 +484,6 @@ int ptep_test_and_clear_young(struct vm_area_struct *vma,
 		ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
 					 (unsigned long *) &ptep->pte);
 
-	if (ret)
-		pte_update(vma->vm_mm, addr, ptep);
-
 	return ret;
 }
 
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 37689a7cc03b..1ab3821f9e26 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -121,8 +121,28 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
 	 * hypothetical buggy code that directly switches to swapper_pg_dir
 	 * without going through leave_mm() / switch_mm_irqs_off() or that
 	 * does something like write_cr3(read_cr3_pa()).
+	 *
+	 * Only do this check if CONFIG_DEBUG_VM=y because __read_cr3()
+	 * isn't free.
 	 */
-	VM_BUG_ON(__read_cr3() != (__sme_pa(real_prev->pgd) | prev_asid));
+#ifdef CONFIG_DEBUG_VM
+	if (WARN_ON_ONCE(__read_cr3() !=
+			 (__sme_pa(real_prev->pgd) | prev_asid))) {
+		/*
+		 * If we were to BUG here, we'd be very likely to kill
+		 * the system so hard that we don't see the call trace.
+		 * Try to recover instead by ignoring the error and doing
+		 * a global flush to minimize the chance of corruption.
+		 *
+		 * (This is far from being a fully correct recovery.
+		 *  Architecturally, the CPU could prefetch something
+		 *  back into an incorrect ASID slot and leave it there
+		 *  to cause trouble down the road.  It's better than
+		 *  nothing, though.)
+		 */
+		__flush_tlb_all();
+	}
+#endif
 
 	if (real_prev == next) {
 		VM_BUG_ON(this_cpu_read(cpu_tlbstate.ctxs[prev_asid].ctx_id) !=
diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c
index f2598d81cd55..f910c514438f 100644
--- a/arch/x86/power/hibernate_64.c
+++ b/arch/x86/power/hibernate_64.c
@@ -295,7 +295,26 @@ int arch_hibernation_header_save(void *addr, unsigned int max_size)
 		return -EOVERFLOW;
 	rdr->jump_address = (unsigned long)restore_registers;
 	rdr->jump_address_phys = __pa_symbol(restore_registers);
-	rdr->cr3 = restore_cr3;
+
+	/*
+	 * The restore code fixes up CR3 and CR4 in the following sequence:
+	 *
+	 * [in hibernation asm]
+	 * 1. CR3 <= temporary page tables
+	 * 2. CR4 <= mmu_cr4_features (from the kernel that restores us)
+	 * 3. CR3 <= rdr->cr3
+	 * 4. CR4 <= mmu_cr4_features (from us, i.e. the image kernel)
+	 * [in restore_processor_state()]
+	 * 5. CR4 <= saved CR4
+	 * 6. CR3 <= saved CR3
+	 *
+	 * Our mmu_cr4_features has CR4.PCIDE=0, and toggling
+	 * CR4.PCIDE while CR3's PCID bits are nonzero is illegal, so
+	 * rdr->cr3 needs to point to valid page tables but must not
+	 * have any of the PCID bits set.
+	 */
+	rdr->cr3 = restore_cr3 & ~CR3_PCID_MASK;
+
 	rdr->magic = RESTORE_MAGIC;
 
 	hibernation_e820_save(rdr->e820_digest);
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index ae2a2e2d6362..69b9deff7e5c 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1038,7 +1038,6 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
 	.read_cr0 = xen_read_cr0,
 	.write_cr0 = xen_write_cr0,
 
-	.read_cr4 = native_read_cr4,
 	.write_cr4 = xen_write_cr4,
 
 #ifdef CONFIG_X86_64
@@ -1073,7 +1072,6 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
 	.alloc_ldt = xen_alloc_ldt,
 	.free_ldt = xen_free_ldt,
 
-	.store_idt = native_store_idt,
 	.store_tr = xen_store_tr,
 
 	.write_ldt_entry = xen_write_ldt_entry,
diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
index 6b983b300666..509f560bd0c6 100644
--- a/arch/x86/xen/mmu_pv.c
+++ b/arch/x86/xen/mmu_pv.c
@@ -2409,8 +2409,6 @@ static const struct pv_mmu_ops xen_mmu_ops __initconst = {
 	.flush_tlb_single = xen_flush_tlb_single,
 	.flush_tlb_others = xen_flush_tlb_others,
 
-	.pte_update = paravirt_nop,
-
 	.pgd_alloc = xen_pgd_alloc,
 	.pgd_free = xen_pgd_free,