From: Paul Mackerras <paulus@samba.org>
To: Alexander Graf <agraf@suse.de>
Cc: linuxppc-dev@ozlabs.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org
Subject: [PATCH 02/13] KVM: PPC: Keep a record of HV guest view of hashed page table entries
Date: Tue, 6 Dec 2011 17:03:23 +1100 [thread overview]
Message-ID: <20111206060323.GF12389@drongo> (raw)
In-Reply-To: <20111206060156.GD12389@drongo>
This adds an array that parallels the guest hashed page table (HPT),
that is, it has one entry per HPTE, used to store the guest's view
of the second doubleword of the corresponding HPTE. The first
doubleword in the HPTE is the same as the guest's idea of it, so we
don't need to store a copy, but the second doubleword in the HPTE has
the real page number rather than the guest's logical page number.
This allows us to remove the back_translate() and reverse_xlate()
functions.
This "reverse mapping" array is vmalloc'd, meaning that to access it
in real mode we have to walk the kernel's page tables explicitly.
That is done by the new real_vmalloc_addr() function. (In fact this
returns an address in the linear mapping, so the result is usable
both in real mode and in virtual mode.)
There are also some minor cleanups here: moving the definitions of
HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3.
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
arch/powerpc/include/asm/kvm_book3s_64.h | 8 +++
arch/powerpc/include/asm/kvm_host.h | 10 ++++
arch/powerpc/kvm/book3s_64_mmu_hv.c | 44 +++++++++++----
arch/powerpc/kvm/book3s_hv_rm_mmu.c | 87 ++++++++++++++++++------------
4 files changed, 103 insertions(+), 46 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index d0ac94f..23bb17e 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -29,6 +29,14 @@ static inline struct kvmppc_book3s_shadow_vcpu *to_svcpu(struct kvm_vcpu *vcpu)
#define SPAPR_TCE_SHIFT 12
+#ifdef CONFIG_KVM_BOOK3S_64_HV
+/* For now use fixed-size 16MB page table */
+#define HPT_ORDER 24
+#define HPT_NPTEG (1ul << (HPT_ORDER - 7)) /* 128B per pteg */
+#define HPT_NPTE (HPT_NPTEG << 3) /* 8 PTEs per PTEG */
+#define HPT_HASH_MASK (HPT_NPTEG - 1)
+#endif
+
static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
unsigned long pte_index)
{
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 66c75cd..629df2e 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -166,9 +166,19 @@ struct kvmppc_rma_info {
atomic_t use_count;
};
+/*
+ * The reverse mapping array has one entry for each HPTE,
+ * which stores the guest's view of the second word of the HPTE
+ * (including the guest physical address of the mapping).
+ */
+struct revmap_entry {
+ unsigned long guest_rpte;
+};
+
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;
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index bc3a2ea..80ece8d 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -23,6 +23,7 @@
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/hugetlb.h>
+#include <linux/vmalloc.h>
#include <asm/tlbflush.h>
#include <asm/kvm_ppc.h>
@@ -33,11 +34,6 @@
#include <asm/ppc-opcode.h>
#include <asm/cputable.h>
-/* For now use fixed-size 16MB page table */
-#define HPT_ORDER 24
-#define HPT_NPTEG (1ul << (HPT_ORDER - 7)) /* 128B per pteg */
-#define HPT_HASH_MASK (HPT_NPTEG - 1)
-
/* Pages in the VRMA are 16MB pages */
#define VRMA_PAGE_ORDER 24
#define VRMA_VSID 0x1ffffffUL /* 1TB VSID reserved for VRMA */
@@ -51,7 +47,9 @@ long kvmppc_alloc_hpt(struct kvm *kvm)
{
unsigned long hpt;
unsigned long lpid;
+ struct revmap_entry *rev;
+ /* Allocate guest's hashed page table */
hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|__GFP_NOWARN,
HPT_ORDER - PAGE_SHIFT);
if (!hpt) {
@@ -60,12 +58,20 @@ long kvmppc_alloc_hpt(struct kvm *kvm)
}
kvm->arch.hpt_virt = hpt;
+ /* Allocate reverse map array */
+ rev = vmalloc(sizeof(struct revmap_entry) * HPT_NPTE);
+ if (!rev) {
+ pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n");
+ goto out_freehpt;
+ }
+ kvm->arch.revmap = rev;
+
+ /* Allocate the guest's logical partition ID */
do {
lpid = find_first_zero_bit(lpid_inuse, NR_LPIDS);
if (lpid >= NR_LPIDS) {
pr_err("kvm_alloc_hpt: No LPIDs free\n");
- free_pages(hpt, HPT_ORDER - PAGE_SHIFT);
- return -ENOMEM;
+ goto out_freeboth;
}
} while (test_and_set_bit(lpid, lpid_inuse));
@@ -74,11 +80,18 @@ long kvmppc_alloc_hpt(struct kvm *kvm)
pr_info("KVM guest htab at %lx, LPID %lx\n", hpt, lpid);
return 0;
+
+ out_freeboth:
+ vfree(rev);
+ out_freehpt:
+ free_pages(hpt, HPT_ORDER - PAGE_SHIFT);
+ return -ENOMEM;
}
void kvmppc_free_hpt(struct kvm *kvm)
{
clear_bit(kvm->arch.lpid, lpid_inuse);
+ vfree(kvm->arch.revmap);
free_pages(kvm->arch.hpt_virt, HPT_ORDER - PAGE_SHIFT);
}
@@ -89,14 +102,16 @@ void kvmppc_map_vrma(struct kvm *kvm, struct kvm_userspace_memory_region *mem)
unsigned long pfn;
unsigned long *hpte;
unsigned long hash;
+ unsigned long porder = kvm->arch.ram_porder;
+ struct revmap_entry *rev;
struct kvmppc_pginfo *pginfo = kvm->arch.ram_pginfo;
if (!pginfo)
return;
/* VRMA can't be > 1TB */
- if (npages > 1ul << (40 - kvm->arch.ram_porder))
- npages = 1ul << (40 - kvm->arch.ram_porder);
+ if (npages > 1ul << (40 - porder))
+ npages = 1ul << (40 - porder);
/* Can't use more than 1 HPTE per HPTEG */
if (npages > HPT_NPTEG)
npages = HPT_NPTEG;
@@ -113,15 +128,20 @@ void kvmppc_map_vrma(struct kvm *kvm, struct kvm_userspace_memory_region *mem)
* at most one HPTE per HPTEG, we just assume entry 7
* is available and use it.
*/
- hpte = (unsigned long *) (kvm->arch.hpt_virt + (hash << 7));
- hpte += 7 * 2;
+ hash = (hash << 3) + 7;
+ hpte = (unsigned long *) (kvm->arch.hpt_virt + (hash << 4));
/* HPTE low word - RPN, protection, etc. */
hpte[1] = (pfn << PAGE_SHIFT) | HPTE_R_R | HPTE_R_C |
HPTE_R_M | PP_RWXX;
- wmb();
+ smp_wmb();
hpte[0] = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
(i << (VRMA_PAGE_ORDER - 16)) | HPTE_V_BOLTED |
HPTE_V_LARGE | HPTE_V_VALID;
+
+ /* Reverse map info */
+ rev = &kvm->arch.revmap[hash];
+ rev->guest_rpte = (i << porder) | HPTE_R_R | HPTE_R_C |
+ HPTE_R_M | PP_RWXX;
}
}
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index bacb0cf..6148493 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -20,10 +20,19 @@
#include <asm/synch.h>
#include <asm/ppc-opcode.h>
-/* For now use fixed-size 16MB page table */
-#define HPT_ORDER 24
-#define HPT_NPTEG (1ul << (HPT_ORDER - 7)) /* 128B per pteg */
-#define HPT_HASH_MASK (HPT_NPTEG - 1)
+/* Translate address of a vmalloc'd thing to a linear map address */
+static void *real_vmalloc_addr(void *x)
+{
+ unsigned long addr = (unsigned long) x;
+ pte_t *p;
+
+ p = find_linux_pte(swapper_pg_dir, addr);
+ if (!p || !pte_present(*p))
+ return NULL;
+ /* assume we don't have huge pages in vmalloc space... */
+ addr = (pte_pfn(*p) << PAGE_SHIFT) | (addr & ~PAGE_MASK);
+ return __va(addr);
+}
#define HPTE_V_HVLOCK 0x40UL
@@ -52,6 +61,8 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
struct kvm *kvm = vcpu->kvm;
unsigned long i, lpn, pa;
unsigned long *hpte;
+ struct revmap_entry *rev;
+ unsigned long g_ptel = ptel;
/* only handle 4k, 64k and 16M pages for now */
porder = 12;
@@ -82,7 +93,7 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
pteh &= ~0x60UL;
ptel &= ~(HPTE_R_PP0 - kvm->arch.ram_psize);
ptel |= pa;
- if (pte_index >= (HPT_NPTEG << 3))
+ if (pte_index >= HPT_NPTE)
return H_PARAMETER;
if (likely((flags & H_EXACT) == 0)) {
pte_index &= ~7UL;
@@ -95,18 +106,22 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
break;
hpte += 2;
}
+ pte_index += i;
} else {
- i = 0;
hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
if (!lock_hpte(hpte, HPTE_V_HVLOCK | HPTE_V_VALID))
return H_PTEG_FULL;
}
+
+ /* Save away the guest's idea of the second HPTE dword */
+ rev = real_vmalloc_addr(&kvm->arch.revmap[pte_index]);
+ if (rev)
+ rev->guest_rpte = g_ptel;
hpte[1] = ptel;
eieio();
hpte[0] = pteh;
asm volatile("ptesync" : : : "memory");
- atomic_inc(&kvm->arch.ram_pginfo[lpn].refcnt);
- vcpu->arch.gpr[4] = pte_index + i;
+ vcpu->arch.gpr[4] = pte_index;
return H_SUCCESS;
}
@@ -138,7 +153,7 @@ long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
unsigned long *hpte;
unsigned long v, r, rb;
- if (pte_index >= (HPT_NPTEG << 3))
+ if (pte_index >= HPT_NPTE)
return H_PARAMETER;
hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
while (!lock_hpte(hpte, HPTE_V_HVLOCK))
@@ -193,7 +208,7 @@ long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
if (req == 3)
break;
if (req != 1 || flags == 3 ||
- pte_index >= (HPT_NPTEG << 3)) {
+ pte_index >= HPT_NPTE) {
/* parameter error */
args[i * 2] = ((0xa0 | flags) << 56) + pte_index;
ret = H_PARAMETER;
@@ -256,9 +271,10 @@ long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
{
struct kvm *kvm = vcpu->kvm;
unsigned long *hpte;
- unsigned long v, r, rb;
+ struct revmap_entry *rev;
+ unsigned long v, r, rb, mask, bits;
- if (pte_index >= (HPT_NPTEG << 3))
+ if (pte_index >= HPT_NPTE)
return H_PARAMETER;
hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
while (!lock_hpte(hpte, HPTE_V_HVLOCK))
@@ -271,11 +287,21 @@ long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
if (atomic_read(&kvm->online_vcpus) == 1)
flags |= H_LOCAL;
v = hpte[0];
- r = hpte[1] & ~(HPTE_R_PP0 | HPTE_R_PP | HPTE_R_N |
- HPTE_R_KEY_HI | HPTE_R_KEY_LO);
- r |= (flags << 55) & HPTE_R_PP0;
- r |= (flags << 48) & HPTE_R_KEY_HI;
- r |= flags & (HPTE_R_PP | HPTE_R_N | HPTE_R_KEY_LO);
+ bits = (flags << 55) & HPTE_R_PP0;
+ bits |= (flags << 48) & HPTE_R_KEY_HI;
+ bits |= flags & (HPTE_R_PP | HPTE_R_N | HPTE_R_KEY_LO);
+
+ /* Update guest view of 2nd HPTE dword */
+ mask = HPTE_R_PP0 | HPTE_R_PP | HPTE_R_N |
+ HPTE_R_KEY_HI | HPTE_R_KEY_LO;
+ rev = real_vmalloc_addr(&kvm->arch.revmap[pte_index]);
+ if (rev) {
+ r = (rev->guest_rpte & ~mask) | bits;
+ rev->guest_rpte = r;
+ }
+ r = (hpte[1] & ~mask) | bits;
+
+ /* Update HPTE */
rb = compute_tlbie_rb(v, r, pte_index);
hpte[0] = v & ~HPTE_V_VALID;
if (!(flags & H_LOCAL)) {
@@ -298,38 +324,31 @@ long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
return H_SUCCESS;
}
-static unsigned long reverse_xlate(struct kvm *kvm, unsigned long realaddr)
-{
- long int i;
- unsigned long offset, rpn;
-
- offset = realaddr & (kvm->arch.ram_psize - 1);
- rpn = (realaddr - offset) >> PAGE_SHIFT;
- for (i = 0; i < kvm->arch.ram_npages; ++i)
- if (rpn == kvm->arch.ram_pginfo[i].pfn)
- return (i << PAGE_SHIFT) + offset;
- return HPTE_R_RPN; /* all 1s in the RPN field */
-}
-
long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
unsigned long pte_index)
{
struct kvm *kvm = vcpu->kvm;
unsigned long *hpte, r;
int i, n = 1;
+ struct revmap_entry *rev = NULL;
- if (pte_index >= (HPT_NPTEG << 3))
+ if (pte_index >= HPT_NPTE)
return H_PARAMETER;
if (flags & H_READ_4) {
pte_index &= ~3;
n = 4;
}
+ if (flags & H_R_XLATE)
+ rev = real_vmalloc_addr(&kvm->arch.revmap[pte_index]);
for (i = 0; i < n; ++i, ++pte_index) {
hpte = (unsigned long *)(kvm->arch.hpt_virt + (pte_index << 4));
r = hpte[1];
- if ((flags & H_R_XLATE) && (hpte[0] & HPTE_V_VALID))
- r = reverse_xlate(kvm, r & HPTE_R_RPN) |
- (r & ~HPTE_R_RPN);
+ if (hpte[0] & HPTE_V_VALID) {
+ if (rev)
+ r = rev[i].guest_rpte;
+ else
+ r = hpte[1] | HPTE_R_RPN;
+ }
vcpu->arch.gpr[4 + i * 2] = hpte[0];
vcpu->arch.gpr[5 + i * 2] = r;
}
--
1.7.5.4
next prev parent reply other threads:[~2011-12-06 6:03 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-06 6:01 [PATCH 0/13] KVM: PPC: Update Book3S HV memory handling Paul Mackerras
2011-12-06 6:02 ` [PATCH 01/13] KVM: PPC: Move kvm_vcpu_ioctl_[gs]et_one_reg down to platform-specific code Paul Mackerras
2011-12-06 6:03 ` Paul Mackerras [this message]
2011-12-06 6:04 ` [PATCH 03/13] KVM: PPC: Keep page physical addresses in per-slot arrays Paul Mackerras
2011-12-06 6:07 ` [PATCH 04/13] KVM: PPC: Add an interface for pinning guest pages in Book3s HV guests Paul Mackerras
2011-12-06 6:08 ` [PATCH 05/13] KVM: PPC: Make the H_ENTER hcall more reliable Paul Mackerras
2011-12-06 6:08 ` [PATCH 06/13] KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() Paul Mackerras
2011-12-06 6:09 ` [PATCH 07/13] KVM: PPC: Allow use of small pages to back Book3S HV guests Paul Mackerras
2011-12-06 6:09 ` [PATCH 08/13] KVM: PPC: Allow I/O mappings in memory slots Paul Mackerras
2011-12-06 6:10 ` [PATCH 09/13] KVM: PPC: Maintain a doubly-linked list of guest HPTEs for each gfn Paul Mackerras
2011-12-06 6:10 ` [PATCH 10/13] KVM: PPC: Implement MMIO emulation support for Book3S HV guests Paul Mackerras
2011-12-06 6:13 ` [PATCH 11/13] KVM: Add barriers to allow mmu_notifier_retry to be used locklessly Paul Mackerras
2011-12-06 6:14 ` [PATCH 12/13] KVM: PPC: Implement MMU notifiers for Book3S HV guests Paul Mackerras
2011-12-06 6:14 ` [PATCH 13/13] KVM: PPC: Allow for read-only pages backing a Book3S HV guest Paul Mackerras
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