| Message ID | 20161215055404.29351-8-david@gibson.dropbear.id.au (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 15.12.2016 06:54, David Gibson wrote: > 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 8e5ac2f..cd145eb 100644 > --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c > +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c > @@ -740,13 +740,53 @@ 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]); > + } > + } Superfluous TAB at the end of above line. Apart from that, the patch looks fine to me. Thomas -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 8e5ac2f..cd145eb 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -740,13 +740,53 @@ 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); @@ -769,37 +809,8 @@ 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])); }
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(-)