From: David Gibson <david@gibson.dropbear.id.au>
To: paulus@samba.org, sjitindarsingh@gmail.com
Cc: benh@kernel.crashing.org, thuth@redhat.com, lvivier@redhat.com,
linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org,
David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCHv2 08/11] powerpc/kvm: Create kvmppc_unmap_hpte_helper()
Date: Tue, 20 Dec 2016 16:49:04 +1100 [thread overview]
Message-ID: <20161220054907.9204-9-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20161220054907.9204-1-david@gibson.dropbear.id.au>
The kvm_unmap_rmapp() function, called from certain MMU notifiers, is used
to force all guest mappings of a particular host page to be set ABSENT, and
removed from the reverse mappings.
For HPT resizing, we will have some cases where we want to set just a
single guest HPTE ABSENT and remove its reverse mappings. To prepare with
this, we split out the logic from kvm_unmap_rmapp() to evict a single HPTE,
moving it to a new helper function.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
arch/powerpc/kvm/book3s_64_mmu_hv.c | 77 +++++++++++++++++++++----------------
1 file changed, 44 insertions(+), 33 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 2765d04..74e909a 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -738,13 +738,53 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
return kvm_handle_hva_range(kvm, hva, hva + 1, handler);
}
+/* Must be called with both HPTE and rmap locked */
+static void kvmppc_unmap_hpte(struct kvm *kvm, unsigned long i,
+ unsigned long *rmapp, unsigned long gfn)
+{
+ __be64 *hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
+ struct revmap_entry *rev = kvm->arch.hpt.rev;
+ unsigned long j, h;
+ unsigned long ptel, psize, rcbits;
+
+ j = rev[i].forw;
+ if (j == i) {
+ /* chain is now empty */
+ *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
+ } else {
+ /* remove i from chain */
+ h = rev[i].back;
+ rev[h].forw = j;
+ rev[j].back = h;
+ rev[i].forw = rev[i].back = i;
+ *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
+ }
+
+ /* Now check and modify the HPTE */
+ ptel = rev[i].guest_rpte;
+ psize = hpte_page_size(be64_to_cpu(hptep[0]), ptel);
+ if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
+ hpte_rpn(ptel, psize) == gfn) {
+ hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
+ kvmppc_invalidate_hpte(kvm, hptep, i);
+ hptep[1] &= ~cpu_to_be64(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
+ /* Harvest R and C */
+ rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
+ *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
+ if (rcbits & HPTE_R_C)
+ kvmppc_update_rmap_change(rmapp, psize);
+ if (rcbits & ~rev[i].guest_rpte) {
+ rev[i].guest_rpte = ptel | rcbits;
+ note_hpte_modification(kvm, &rev[i]);
+ }
+ }
+}
+
static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
unsigned long gfn)
{
- struct revmap_entry *rev = kvm->arch.hpt.rev;
- unsigned long h, i, j;
+ unsigned long i;
__be64 *hptep;
- unsigned long ptel, psize, rcbits;
for (;;) {
lock_rmap(rmapp);
@@ -767,37 +807,8 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
cpu_relax();
continue;
}
- j = rev[i].forw;
- if (j == i) {
- /* chain is now empty */
- *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
- } else {
- /* remove i from chain */
- h = rev[i].back;
- rev[h].forw = j;
- rev[j].back = h;
- rev[i].forw = rev[i].back = i;
- *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
- }
- /* Now check and modify the HPTE */
- ptel = rev[i].guest_rpte;
- psize = hpte_page_size(be64_to_cpu(hptep[0]), ptel);
- if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
- hpte_rpn(ptel, psize) == gfn) {
- hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
- kvmppc_invalidate_hpte(kvm, hptep, i);
- hptep[1] &= ~cpu_to_be64(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
- /* Harvest R and C */
- rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
- *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
- if (rcbits & HPTE_R_C)
- kvmppc_update_rmap_change(rmapp, psize);
- if (rcbits & ~rev[i].guest_rpte) {
- rev[i].guest_rpte = ptel | rcbits;
- note_hpte_modification(kvm, &rev[i]);
- }
- }
+ kvmppc_unmap_hpte(kvm, i, rmapp, gfn);
unlock_rmap(rmapp);
__unlock_hpte(hptep, be64_to_cpu(hptep[0]));
}
--
2.9.3
next prev parent reply other threads:[~2016-12-20 5:51 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-20 5:48 [PATCHv2 00/11] KVM implementation of PAPR HPT resizing extension David Gibson
2016-12-20 5:48 ` [PATCHv2 01/11] Documentation: Correct duplicate section number in kvm/api.txt David Gibson
2016-12-20 5:48 ` [PATCHv2 02/11] powerpc/kvm: HPT resizing documentation and reserved numbers David Gibson
2016-12-20 5:48 ` [PATCHv2 03/11] powerpc/kvm: Rename kvm_alloc_hpt() for clarity David Gibson
2016-12-20 5:49 ` [PATCHv2 04/11] powerpc/kvm: Gather HPT related variables into sub-structure David Gibson
2016-12-20 5:49 ` [PATCHv2 05/11] powerpc/kvm: Don't store values derivable from HPT order David Gibson
2016-12-20 5:49 ` [PATCHv2 06/11] powerpc/kvm: Split HPT allocation from activation David Gibson
2016-12-20 5:49 ` [PATCHv2 07/11] powerpc/kvm: Allow KVM_PPC_ALLOCATE_HTAB ioctl() to change HPT size David Gibson
2016-12-20 5:49 ` David Gibson [this message]
2016-12-20 5:49 ` [PATCHv2 09/11] powerpc/kvm: Outline of KVM-HV HPT resizing implementation David Gibson
2016-12-20 5:49 ` [PATCHv2 10/11] powerpc/kvm: " David Gibson
2016-12-20 5:49 ` [PATCHv2 11/11] powerpc/kvm: Advertise availablity of HPT resizing on KVM HV David Gibson
2017-01-31 22:18 ` [PATCHv2 00/11] KVM implementation of PAPR HPT resizing extension Paul Mackerras
2017-02-01 4:56 ` David Gibson
2017-02-01 5:07 ` Paul Mackerras
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