Merge branch 'kvm-ppc-next' of git://git.kernel.org/pub/scm/linux/ker…

…nel/git/paulus/powerpc

KVM/PPC update for 4.14

There are various minor fixes and cleanups.  The only new feature is
that we now export information about storage key support to userspace,
so it can advertise it to the guest.

I have pulled in Michael Ellerman's topic/ppc-kvm branch from the
powerpc tree to get a couple of fixes that touch both KVM PPC code and
other PPC code.  That's why there is some arch/powerpc stuff in the
diffstat that isn't arch/powerpc/kvm.

arch/powerpc/include/asm/book3s/64/mmu-hash.h

@@ -104,6 +104,7 @@
 #define HPTE_R_C		ASM_CONST(0x0000000000000080)
 #define HPTE_R_R		ASM_CONST(0x0000000000000100)
 #define HPTE_R_KEY_LO		ASM_CONST(0x0000000000000e00)
+#define HPTE_R_KEY		(HPTE_R_KEY_LO | HPTE_R_KEY_HI)
 
 #define HPTE_V_1TB_SEG		ASM_CONST(0x4000000000000000)
 #define HPTE_V_VRMA_MASK	ASM_CONST(0x4001ffffff000000)

arch/powerpc/include/asm/kvm_book3s_asm.h

@@ -104,6 +104,10 @@ struct kvmppc_host_state {
 	u8 napping;
 
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	/*
+	 * hwthread_req/hwthread_state pair is used to pull sibling threads
+	 * out of guest on pre-ISAv3.0B CPUs where threads share MMU.
+	 */
 	u8 hwthread_req;
 	u8 hwthread_state;
 	u8 host_ipi;

arch/powerpc/include/asm/pgtable.h

@@ -66,16 +66,8 @@ extern int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
 #ifndef CONFIG_TRANSPARENT_HUGEPAGE
 #define pmd_large(pmd)		0
 #endif
-pte_t *__find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
-				   bool *is_thp, unsigned *shift);
-static inline pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
-					       bool *is_thp, unsigned *shift)
-{
-	VM_WARN(!arch_irqs_disabled(),
-		"%s called with irq enabled\n", __func__);
-	return __find_linux_pte_or_hugepte(pgdir, ea, is_thp, shift);
-}
 
+/* can we use this in kvm */
 unsigned long vmalloc_to_phys(void *vmalloc_addr);
 
 void pgtable_cache_add(unsigned shift, void (*ctor)(void *));

arch/powerpc/include/asm/pte-walk.h

@@ -0,0 +1,35 @@
+#ifndef _ASM_POWERPC_PTE_WALK_H
+#define _ASM_POWERPC_PTE_WALK_H
+
+#include <linux/sched.h>
+
+/* Don't use this directly */
+extern pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
+			       bool *is_thp, unsigned *hshift);
+
+static inline pte_t *find_linux_pte(pgd_t *pgdir, unsigned long ea,
+				    bool *is_thp, unsigned *hshift)
+{
+	VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
+	return __find_linux_pte(pgdir, ea, is_thp, hshift);
+}
+
+static inline pte_t *find_init_mm_pte(unsigned long ea, unsigned *hshift)
+{
+	pgd_t *pgdir = init_mm.pgd;
+	return __find_linux_pte(pgdir, ea, NULL, hshift);
+}
+/*
+ * This is what we should always use. Any other lockless page table lookup needs
+ * careful audit against THP split.
+ */
+static inline pte_t *find_current_mm_pte(pgd_t *pgdir, unsigned long ea,
+					 bool *is_thp, unsigned *hshift)
+{
+	VM_WARN(!arch_irqs_disabled(), "%s called with irq enabled\n", __func__);
+	VM_WARN(pgdir != current->mm->pgd,
+		"%s lock less page table lookup called on wrong mm\n", __func__);
+	return __find_linux_pte(pgdir, ea, is_thp, hshift);
+}
+
+#endif /* _ASM_POWERPC_PTE_WALK_H */

arch/powerpc/kernel/eeh.c

@@ -44,6 +44,7 @@
 #include <asm/machdep.h>
 #include <asm/ppc-pci.h>
 #include <asm/rtas.h>
+#include <asm/pte-walk.h>
 
 
 /** Overview:
@@ -352,8 +353,7 @@ static inline unsigned long eeh_token_to_phys(unsigned long token)
 	 * worried about _PAGE_SPLITTING/collapse. Also we will not hit
 	 * page table free, because of init_mm.
 	 */
-	ptep = __find_linux_pte_or_hugepte(init_mm.pgd, token,
-					   NULL, &hugepage_shift);
+	ptep = find_init_mm_pte(token, &hugepage_shift);
 	if (!ptep)
 		return token;
 	WARN_ON(hugepage_shift);

arch/powerpc/kernel/idle_book3s.S

@@ -242,13 +242,20 @@ enter_winkle:
 /*
  * r3 - PSSCR value corresponding to the requested stop state.
  */
-power_enter_stop:
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-	/* Tell KVM we're entering idle */
+power_enter_stop_kvm_rm:
+	/*
+	 * This is currently unused because POWER9 KVM does not have to
+	 * gather secondary threads into sibling mode, but the code is
+	 * here in case that function is required.
+	 *
+	 * Tell KVM we're entering idle.
+	 */
 	li	r4,KVM_HWTHREAD_IN_IDLE
 	/* DO THIS IN REAL MODE!  See comment above. */
 	stb	r4,HSTATE_HWTHREAD_STATE(r13)
 #endif
+power_enter_stop:
 /*
  * Check if we are executing the lite variant with ESL=EC=0
  */
@@ -411,6 +418,18 @@ pnv_powersave_wakeup_mce:
 
 	b	pnv_powersave_wakeup
 
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+kvm_start_guest_check:
+	li	r0,KVM_HWTHREAD_IN_KERNEL
+	stb	r0,HSTATE_HWTHREAD_STATE(r13)
+	/* Order setting hwthread_state vs. testing hwthread_req */
+	sync
+	lbz	r0,HSTATE_HWTHREAD_REQ(r13)
+	cmpwi	r0,0
+	beqlr
+	b	kvm_start_guest
+#endif
+
 /*
  * Called from reset vector for powersave wakeups.
  * cr3 - set to gt if waking up with partial/complete hypervisor state loss
@@ -435,15 +454,9 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
 	mr	r3,r12
 
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-	li	r0,KVM_HWTHREAD_IN_KERNEL
-	stb	r0,HSTATE_HWTHREAD_STATE(r13)
-	/* Order setting hwthread_state vs. testing hwthread_req */
-	sync
-	lbz	r0,HSTATE_HWTHREAD_REQ(r13)
-	cmpwi	r0,0
-	beq	1f
-	b	kvm_start_guest
-1:
+BEGIN_FTR_SECTION
+	bl	kvm_start_guest_check
+END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 #endif
 
 	/* Return SRR1 from power7_nap() */

arch/powerpc/kernel/io-workarounds.c

@@ -19,6 +19,8 @@
 #include <asm/pgtable.h>
 #include <asm/ppc-pci.h>
 #include <asm/io-workarounds.h>
+#include <asm/pte-walk.h>
+
 
 #define IOWA_MAX_BUS	8
 
@@ -75,8 +77,7 @@ struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
 		 * We won't find huge pages here (iomem). Also can't hit
 		 * a page table free due to init_mm
 		 */
-		ptep = __find_linux_pte_or_hugepte(init_mm.pgd, vaddr,
-						   NULL, &hugepage_shift);
+		ptep = find_init_mm_pte(vaddr, &hugepage_shift);
 		if (ptep == NULL)
 			paddr = 0;
 		else {

arch/powerpc/kvm/book3s_64_mmu_hv.c

@@ -37,6 +37,7 @@
 #include <asm/synch.h>
 #include <asm/ppc-opcode.h>
 #include <asm/cputable.h>
+#include <asm/pte-walk.h>
 
 #include "trace_hv.h"
 
@@ -599,8 +600,8 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 			 * hugepage split and collapse.
 			 */
 			local_irq_save(flags);
-			ptep = find_linux_pte_or_hugepte(current->mm->pgd,
-							 hva, NULL, NULL);
+			ptep = find_current_mm_pte(current->mm->pgd,
+						   hva, NULL, NULL);
 			if (ptep) {
 				pte = kvmppc_read_update_linux_pte(ptep, 1);
 				if (__pte_write(pte))
@@ -1940,6 +1941,7 @@ int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
 	rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
 	ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
 	if (ret < 0) {
+		kfree(ctx);
 		kvm_put_kvm(kvm);
 		return ret;
 	}

arch/powerpc/kvm/book3s_64_mmu_radix.c

@@ -17,6 +17,7 @@
 #include <asm/mmu.h>
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
+#include <asm/pte-walk.h>
 
 /*
  * Supported radix tree geometry.
@@ -359,8 +360,7 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 		if (writing)
 			pgflags |= _PAGE_DIRTY;
 		local_irq_save(flags);
-		ptep = __find_linux_pte_or_hugepte(current->mm->pgd, hva,
-						   NULL, NULL);
+		ptep = find_current_mm_pte(current->mm->pgd, hva, NULL, NULL);
 		if (ptep) {
 			pte = READ_ONCE(*ptep);
 			if (pte_present(pte) &&
@@ -374,8 +374,12 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 				spin_unlock(&kvm->mmu_lock);
 				return RESUME_GUEST;
 			}
-			ptep = __find_linux_pte_or_hugepte(kvm->arch.pgtable,
-							gpa, NULL, &shift);
+			/*
+			 * We are walking the secondary page table here. We can do this
+			 * without disabling irq.
+			 */
+			ptep = __find_linux_pte(kvm->arch.pgtable,
+						gpa, NULL, &shift);
 			if (ptep && pte_present(*ptep)) {
 				kvmppc_radix_update_pte(kvm, ptep, 0, pgflags,
 							gpa, shift);
@@ -427,8 +431,8 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 			pgflags |= _PAGE_WRITE;
 		} else {
 			local_irq_save(flags);
-			ptep = __find_linux_pte_or_hugepte(current->mm->pgd,
-							hva, NULL, NULL);
+			ptep = find_current_mm_pte(current->mm->pgd,
+						   hva, NULL, NULL);
 			if (ptep && pte_write(*ptep) && pte_dirty(*ptep))
 				pgflags |= _PAGE_WRITE;
 			local_irq_restore(flags);
@@ -499,8 +503,7 @@ int kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
 	unsigned int shift;
 	unsigned long old;
 
-	ptep = __find_linux_pte_or_hugepte(kvm->arch.pgtable, gpa,
-					   NULL, &shift);
+	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
 	if (ptep && pte_present(*ptep)) {
 		old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_PRESENT, 0,
 					      gpa, shift);
@@ -525,8 +528,7 @@ int kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
 	unsigned int shift;
 	int ref = 0;
 
-	ptep = __find_linux_pte_or_hugepte(kvm->arch.pgtable, gpa,
-					   NULL, &shift);
+	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
 	if (ptep && pte_present(*ptep) && pte_young(*ptep)) {
 		kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0,
 					gpa, shift);
@@ -545,8 +547,7 @@ int kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
 	unsigned int shift;
 	int ref = 0;
 
-	ptep = __find_linux_pte_or_hugepte(kvm->arch.pgtable, gpa,
-					   NULL, &shift);
+	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
 	if (ptep && pte_present(*ptep) && pte_young(*ptep))
 		ref = 1;
 	return ref;
@@ -562,8 +563,7 @@ static int kvm_radix_test_clear_dirty(struct kvm *kvm,
 	unsigned int shift;
 	int ret = 0;
 
-	ptep = __find_linux_pte_or_hugepte(kvm->arch.pgtable, gpa,
-					   NULL, &shift);
+	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
 	if (ptep && pte_present(*ptep) && pte_dirty(*ptep)) {
 		ret = 1;
 		if (shift)

arch/powerpc/kvm/book3s_64_vio_hv.c

@@ -39,6 +39,7 @@
 #include <asm/udbg.h>
 #include <asm/iommu.h>
 #include <asm/tce.h>
+#include <asm/pte-walk.h>
 
 #ifdef CONFIG_BUG
 
@@ -353,7 +354,16 @@ static long kvmppc_rm_ua_to_hpa(struct kvm_vcpu *vcpu,
 	pte_t *ptep, pte;
 	unsigned shift = 0;
 
-	ptep = __find_linux_pte_or_hugepte(vcpu->arch.pgdir, ua, NULL, &shift);
+	/*
+	 * Called in real mode with MSR_EE = 0. We are safe here.
+	 * It is ok to do the lookup with arch.pgdir here, because
+	 * we are doing this on secondary cpus and current task there
+	 * is not the hypervisor. Also this is safe against THP in the
+	 * host, because an IPI to primary thread will wait for the secondary
+	 * to exit which will agains result in the below page table walk
+	 * to finish.
+	 */
+	ptep = __find_linux_pte(vcpu->arch.pgdir, ua, NULL, &shift);
 	if (!ptep || !pte_present(*ptep))
 		return -ENXIO;
 	pte = *ptep;

arch/powerpc/kvm/book3s_hv.c

@@ -485,7 +485,13 @@ static unsigned long do_h_register_vpa(struct kvm_vcpu *vcpu,
 
 	switch (subfunc) {
 	case H_VPA_REG_VPA:		/* register VPA */
-		if (len < sizeof(struct lppaca))
+		/*
+		 * The size of our lppaca is 1kB because of the way we align
+		 * it for the guest to avoid crossing a 4kB boundary. We only
+		 * use 640 bytes of the structure though, so we should accept
+		 * clients that set a size of 640.
+		 */
+		if (len < 640)
 			break;
 		vpap = &tvcpu->arch.vpa;
 		err = 0;
@@ -2111,6 +2117,15 @@ static int kvmppc_grab_hwthread(int cpu)
 	struct paca_struct *tpaca;
 	long timeout = 10000;
 
+	/*
+	 * ISA v3.0 idle routines do not set hwthread_state or test
+	 * hwthread_req, so they can not grab idle threads.
+	 */
+	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+		WARN(1, "KVM: can not control sibling threads\n");
+		return -EBUSY;
+	}
+
 	tpaca = &paca[cpu];
 
 	/* Ensure the thread won't go into the kernel if it wakes */
@@ -2145,10 +2160,12 @@ static void kvmppc_release_hwthread(int cpu)
 	struct paca_struct *tpaca;
 
 	tpaca = &paca[cpu];
-	tpaca->kvm_hstate.hwthread_req = 0;
 	tpaca->kvm_hstate.kvm_vcpu = NULL;
 	tpaca->kvm_hstate.kvm_vcore = NULL;
 	tpaca->kvm_hstate.kvm_split_mode = NULL;
+	if (!cpu_has_feature(CPU_FTR_ARCH_300))
+		tpaca->kvm_hstate.hwthread_req = 0;
+
 }
 
 static void radix_flush_cpu(struct kvm *kvm, int cpu, struct kvm_vcpu *vcpu)
@@ -3325,6 +3342,14 @@ static int kvm_vm_ioctl_get_smmu_info_hv(struct kvm *kvm,
 	if (radix_enabled())
 		return -EINVAL;
 
+	/*
+	 * POWER7, POWER8 and POWER9 all support 32 storage keys for data.
+	 * POWER7 doesn't support keys for instruction accesses,
+	 * POWER8 and POWER9 do.
+	 */
+	info->data_keys = 32;
+	info->instr_keys = cpu_has_feature(CPU_FTR_ARCH_207S) ? 32 : 0;
+
 	info->flags = KVM_PPC_PAGE_SIZES_REAL;
 	if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
 		info->flags |= KVM_PPC_1T_SEGMENTS;