[GIT PULL] x86 fixes

Ingo Molnar
2017-09-13T17:54:45Z

Linus,

Please pull the latest x86-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-for-linus

# HEAD: 1278f58cdee63cfbb04e5624474a291c81a7a13b x86/hyper-v: Remove duplicated HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED definition

The main changes are the PCID fixes from Andy, but there's also two hyperv fixes
and two paravirt updates.

out-of-topic modifications in x86-urgent-for-linus:
-----------------------------------------------------
MAINTAINERS # 30c1bbffe629: paravirt: Switch maintainer

Thanks,

Ingo

------------------>
Andy Lutomirski (3):
x86/mm: Get rid of VM_BUG_ON in switch_tlb_irqs_off()
x86/hibernate/64: Mask off CR3's PCID bits in the saved CR3
x86/mm/64: Initialize CR4.PCIDE early

Juergen Gross (2):
x86/paravirt: Remove no longer used paravirt functions
paravirt: Switch maintainer

K. Y. Srinivasan (1):
x86/hyper-V: Allocate the IDT entry early in boot

Vitaly Kuznetsov (1):
x86/hyper-v: Remove duplicated HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED definition

MAINTAINERS | 4 +--
arch/x86/include/asm/desc.h | 3 +--
arch/x86/include/asm/paravirt.h | 37 --------------------------
arch/x86/include/asm/paravirt_types.h | 9 -------
arch/x86/include/asm/pgtable.h | 27 +++----------------
arch/x86/include/asm/special_insns.h | 10 +++----
arch/x86/include/uapi/asm/hyperv.h | 6 -----
arch/x86/kernel/cpu/common.c | 49 +++++------------------------------
arch/x86/kernel/cpu/mshyperv.c | 4 +--
arch/x86/kernel/paravirt.c | 5 ----
arch/x86/kernel/setup.c | 5 +++-
arch/x86/kernel/smpboot.c | 8 +++---
arch/x86/kvm/vmx.c | 2 +-
arch/x86/mm/init.c | 34 ++++++++++++++++++++++++
arch/x86/mm/pgtable.c | 7 +----
arch/x86/mm/tlb.c | 22 +++++++++++++++-
arch/x86/power/hibernate_64.c | 21 ++++++++++++++-
arch/x86/xen/enlighten_pv.c | 2 --
arch/x86/xen/mmu_pv.c | 2 --
19 files changed, 107 insertions(+), 150 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index f46a3225e398..14e76a41b302 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10129,7 +10129,7 @@ F: include/uapi/linux/ppdev.h
F: Documentation/parport*.txt

PARAVIRT_OPS INTERFACE
-M: Jeremy Fitzhardinge <jeremy@goop.org>
+M: Juergen Gross <jgross@suse.com>
M: Chris Wright <chrisw@sous-sol.org>
M: Alok Kataria <akataria@vmware.com>
M: Rusty Russell <rusty@rustcorp.com.au>
@@ -10137,7 +10137,7 @@ L: virtualization@lists.linux-foundation.org
S: Supported
F: Documentation/virtual/paravirt_ops.txt
F: arch/*/kernel/paravirt*
-F: arch/*/include/asm/paravirt.h
+F: arch/*/include/asm/paravirt*.h
F: include/linux/hypervisor.h

PARIDE DRIVERS FOR PARALLEL PORT IDE DEVICES
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,