Re: [PATCH v3 04/14] KVM: PPC: Keep page physical addresses in per-slot arrays

arch/powerpc/kvm/book3s_hv_rm_mmu.c |   41 +++++++++++-
4 files changed, 107 insertions(+), 75 deletions(-)
=20

diff --git a/arch/powerpc/include/asm/kvm_host.h =

index 629df2e..7a17ab5 100644

--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h

@@ -38,6 +38,7 @@

#define KVM_MEMORY_SLOTS 32
/* memory slots that does not exposed to userspace */
#define KVM_PRIVATE_MEM_SLOTS 4
+#define KVM_MEM_SLOTS_NUM (KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS)
=20
#ifdef CONFIG_KVM_MMIO
#define KVM_COALESCED_MMIO_PAGE_OFFSET 1

@@ -175,25 +176,27 @@ struct revmap_entry {

	unsigned long guest_rpte;
};
=20
+/* Low-order bits in kvm->arch.slot_phys[][] */
+#define KVMPPC_GOT_PAGE		0x80
+
struct kvm_arch {
#ifdef CONFIG_KVM_BOOK3S_64_HV
	unsigned long hpt_virt;
	struct revmap_entry *revmap;
-	unsigned long ram_npages;
	unsigned long ram_psize;
	unsigned long ram_porder;
-	struct kvmppc_pginfo *ram_pginfo;
	unsigned int lpid;
	unsigned int host_lpid;
	unsigned long host_lpcr;
	unsigned long sdr1;
	unsigned long host_sdr1;
	int tlbie_lock;
-	int n_rma_pages;
	unsigned long lpcr;
	unsigned long rmor;
	struct kvmppc_rma_info *rma;
	struct list_head spapr_tce_tables;
+	unsigned long *slot_phys[KVM_MEM_SLOTS_NUM];
+	int slot_npages[KVM_MEM_SLOTS_NUM];
	unsigned short last_vcpu[NR_CPUS];
	struct kvmppc_vcore *vcores[KVM_MAX_VCORES];
#endif /* CONFIG_KVM_BOOK3S_64_HV */

diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c =

index 80ece8d..e4c6069 100644

--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c

@@ -98,16 +98,16 @@ void kvmppc_free_hpt(struct kvm *kvm)

void kvmppc_map_vrma(struct kvm *kvm, struct =

{
	unsigned long i;
-	unsigned long npages =3D kvm->arch.ram_npages;
-	unsigned long pfn;
+	unsigned long npages;
+	unsigned long pa;
	unsigned long *hpte;
	unsigned long hash;
	unsigned long porder =3D kvm->arch.ram_porder;
	struct revmap_entry *rev;
-	struct kvmppc_pginfo *pginfo =3D kvm->arch.ram_pginfo;
+	unsigned long *physp;
=20
-	if (!pginfo)
-		return;
+	physp =3D kvm->arch.slot_phys[mem->slot];
+	npages =3D kvm->arch.slot_npages[mem->slot];
=20
	/* VRMA can't be > 1TB */
	if (npages > 1ul << (40 - porder))

@@ -117,9 +117,10 @@ void kvmppc_map_vrma(struct kvm *kvm, struct =

		/*

@@ -131,8 +132,7 @@ void kvmppc_map_vrma(struct kvm *kvm, struct =

		smp_wmb();
		hpte[0] =3D HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
			(i << (VRMA_PAGE_ORDER - 16)) | HPTE_V_BOLTED |

diff --git a/arch/powerpc/kvm/book3s_hv.c =

index da7db14..86d3e4b 100644

--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c

@@ -50,14 +50,6 @@

#include <linux/vmalloc.h>
#include <linux/highmem.h>
=20
-/*
- * For now, limit memory to 64GB and require it to be large pages.
- * This value is chosen because it makes the ram_pginfo array be
- * 64kB in size, which is about as large as we want to be trying
- * to allocate with kmalloc.
- */
-#define MAX_MEM_ORDER		36
-
#define LARGE_PAGE_ORDER	24	/* 16MB pages */
=20
/* #define EXIT_DEBUG */

@@ -147,10 +139,12 @@ static unsigned long do_h_register_vpa(struct =

{
	struct kvm *kvm =3D vcpu->kvm;
-	unsigned long pg_index, ra, len;
+	unsigned long gfn, pg_index, ra, len;
	unsigned long pg_offset;
	void *va;
	struct kvm_vcpu *tvcpu;
+	struct kvm_memory_slot *memslot;
+	unsigned long *physp;
=20
	tvcpu =3D kvmppc_find_vcpu(kvm, vcpuid);
	if (!tvcpu)

@@ -164,14 +158,20 @@ static unsigned long do_h_register_vpa(struct =

		if (vpa & 0x7f)
			return H_PARAMETER;
		/* registering new area; convert logical addr to real */
-		pg_index =3D vpa >> kvm->arch.ram_porder;
-		pg_offset =3D vpa & (kvm->arch.ram_psize - 1);
-		if (pg_index >=3D kvm->arch.ram_npages)
+		gfn =3D vpa >> PAGE_SHIFT;
+		memslot =3D gfn_to_memslot(kvm, gfn);
+		if (!memslot || !(memslot->flags & KVM_MEMSLOT_INVALID))
+			return H_PARAMETER;
+		physp =3D kvm->arch.slot_phys[memslot->id];
+		if (!physp)
			return H_PARAMETER;
-		if (kvm->arch.ram_pginfo[pg_index].pfn =3D=3D 0)
+		pg_index =3D (gfn - memslot->base_gfn) >>
+			(kvm->arch.ram_porder - PAGE_SHIFT);
+		pg_offset =3D vpa & (kvm->arch.ram_psize - 1);
+		ra =3D physp[pg_index];
+		if (!ra)
			return H_PARAMETER;
-		ra =3D kvm->arch.ram_pginfo[pg_index].pfn << PAGE_SHIFT;
-		ra |=3D pg_offset;
+		ra =3D (ra & PAGE_MASK) | pg_offset;
		va =3D __va(ra);
		if (flags <=3D 1)
			len =3D *(unsigned short *)(va + 4);

@@ -1108,12 +1108,11 @@ int kvmppc_core_prepare_memory_region(struct =

				struct kvm_userspace_memory_region *mem)
{
	unsigned long psize, porder;
-	unsigned long i, npages, totalpages;
-	unsigned long pg_ix;
-	struct kvmppc_pginfo *pginfo;
+	unsigned long i, npages;
	unsigned long hva;
	struct kvmppc_rma_info *ri =3D NULL;
	struct page *page;
+	unsigned long *phys;
=20
	/* For now, only allow 16MB pages */
	porder =3D LARGE_PAGE_ORDER;

@@ -1125,20 +1124,21 @@ int kvmppc_core_prepare_memory_region(struct =

-
-	/* More memory than we have space to track? */
-	if (totalpages > (1ul << (MAX_MEM_ORDER - LARGE_PAGE_ORDER)))
-		return -EINVAL;
+	phys =3D kvm->arch.slot_phys[mem->slot];
+	if (!phys) {
+		phys =3D vzalloc(npages * sizeof(unsigned long));
+		if (!phys)
+			return -ENOMEM;
+		kvm->arch.slot_phys[mem->slot] =3D phys;
+		kvm->arch.slot_npages[mem->slot] =3D npages;
+	}
=20
	/* Do we already have an RMA registered? */
	if (mem->guest_phys_addr =3D=3D 0 && kvm->arch.rma)
		return -EINVAL;
=20
-	if (totalpages > kvm->arch.ram_npages)
-		kvm->arch.ram_npages =3D totalpages;
-
	/* Is this one of our preallocated RMAs? */
	if (mem->guest_phys_addr =3D=3D 0) {
		struct vm_area_struct *vma;

@@ -1171,7 +1171,6 @@ int kvmppc_core_prepare_memory_region(struct kvm =

		}
		atomic_inc(&ri->use_count);
		kvm->arch.rma =3D ri;
-		kvm->arch.n_rma_pages =3D rma_size >> porder;
=20
		/* Update LPCR and RMOR */
		lpcr =3D kvm->arch.lpcr;

@@ -1195,12 +1194,9 @@ int kvmppc_core_prepare_memory_region(struct =

			continue;
		}
		hva =3D mem->userspace_addr + (i << porder);

@@ -1216,7 +1212,7 @@ int kvmppc_core_prepare_memory_region(struct kvm =

	}
=20
	return 0;

@@ -1225,6 +1221,28 @@ int kvmppc_core_prepare_memory_region(struct =

	return -EINVAL;
}
=20
+static void unpin_slot(struct kvm *kvm, int slot_id)
+{
+	unsigned long *physp;
+	unsigned long j, npages, pfn;
+	struct page *page;
+
+	physp =3D kvm->arch.slot_phys[slot_id];
+	npages =3D kvm->arch.slot_npages[slot_id];
+	if (physp) {
+		for (j =3D 0; j < npages; j++) {
+			if (!(physp[j] & KVMPPC_GOT_PAGE))
+				continue;
+			pfn =3D physp[j] >> PAGE_SHIFT;
+			page =3D pfn_to_page(pfn);
+			SetPageDirty(page);
+			put_page(page);
+		}
+		vfree(physp);
+		kvm->arch.slot_phys[slot_id] =3D NULL;
+	}
+}
+
void kvmppc_core_commit_memory_region(struct kvm *kvm,
				struct kvm_userspace_memory_region *mem)
{

@@ -1236,8 +1254,6 @@ void kvmppc_core_commit_memory_region(struct kvm =

-	long err =3D -ENOMEM;
	unsigned long lpcr;
=20
	/* Allocate hashed page table */

@@ -1247,19 +1263,9 @@ int kvmppc_core_init_vm(struct kvm *kvm)

=20
	INIT_LIST_HEAD(&kvm->arch.spapr_tce_tables);
=20
-	kvm->arch.ram_pginfo =3D kzalloc(npages * sizeof(struct =

-		       npages * sizeof(struct kvmppc_pginfo));
-		goto out_free;
-	}
-
-	kvm->arch.ram_npages =3D 0;
	kvm->arch.ram_psize =3D 1ul << LARGE_PAGE_ORDER;
	kvm->arch.ram_porder =3D LARGE_PAGE_ORDER;
	kvm->arch.rma =3D NULL;
-	kvm->arch.n_rma_pages =3D 0;
=20
	kvm->arch.host_sdr1 =3D mfspr(SPRN_SDR1);
=20

@@ -1282,25 +1288,15 @@ int kvmppc_core_init_vm(struct kvm *kvm)

	kvm->arch.lpcr =3D lpcr;
=20
	return 0;
-
- out_free:
-	kvmppc_free_hpt(kvm);
-	return err;
}
=20
void kvmppc_core_destroy_vm(struct kvm *kvm)
{
-	struct kvmppc_pginfo *pginfo;
	unsigned long i;
=20
-	if (kvm->arch.ram_pginfo) {
-		pginfo =3D kvm->arch.ram_pginfo;
-		kvm->arch.ram_pginfo =3D NULL;
-		for (i =3D kvm->arch.n_rma_pages; i < =

-			if (pginfo[i].pfn)
-				put_page(pfn_to_page(pginfo[i].pfn));
-		kfree(pginfo);
-	}
+	for (i =3D 0; i < KVM_MEM_SLOTS_NUM; i++)
+		unpin_slot(kvm, i);
+
	if (kvm->arch.rma) {
		kvm_release_rma(kvm->arch.rma);
		kvm->arch.rma =3D NULL;

diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c =

index 6148493..84dae82 100644

--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c

@@ -20,6 +20,25 @@

#include <asm/synch.h>
#include <asm/ppc-opcode.h>
=20
+/*
+ * Since this file is built in even if KVM is a module, we need
+ * a local copy of this function for the case where kvm_main.c is
+ * modular.
+ */
+static struct kvm_memory_slot *builtin_gfn_to_memslot(struct kvm =