| Message ID | 20190822102620.21897-3-bharata@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVMPPC driver to manage secure guest pages | expand |
> A secure guest will share some of its pages with hypervisor (Eg. virtio > bounce buffers etc). Support sharing of pages between hypervisor and > ultravisor. > > Once a secure page is converted to shared page, the device page is > unmapped from the HV side page tables. > > Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> > --- > arch/powerpc/include/asm/hvcall.h | 3 ++ > arch/powerpc/kvm/book3s_hv_devm.c | 70 +++++++++++++++++++++++++++++-- > 2 files changed, 69 insertions(+), 4 deletions(-) > > diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h > index 2f6b952deb0f..05b8536f6653 100644 > --- a/arch/powerpc/include/asm/hvcall.h > +++ b/arch/powerpc/include/asm/hvcall.h > @@ -337,6 +337,9 @@ > #define H_TLB_INVALIDATE 0xF808 > #define H_COPY_TOFROM_GUEST 0xF80C > > +/* Flags for H_SVM_PAGE_IN */ > +#define H_PAGE_IN_SHARED 0x1 > + > /* Platform-specific hcalls used by the Ultravisor */ > #define H_SVM_PAGE_IN 0xEF00 > #define H_SVM_PAGE_OUT 0xEF04 > diff --git a/arch/powerpc/kvm/book3s_hv_devm.c b/arch/powerpc/kvm/book3s_hv_devm.c > index 13722f27fa7d..6a3229b78fed 100644 > --- a/arch/powerpc/kvm/book3s_hv_devm.c > +++ b/arch/powerpc/kvm/book3s_hv_devm.c > @@ -46,6 +46,7 @@ struct kvmppc_devm_page_pvt { > unsigned long *rmap; > unsigned int lpid; > unsigned long gpa; > + bool skip_page_out; > }; > > /* > @@ -139,6 +140,54 @@ kvmppc_devm_migrate_alloc_and_copy(struct migrate_vma *mig, > return 0; > } > > +/* > + * Shares the page with HV, thus making it a normal page. > + * > + * - If the page is already secure, then provision a new page and share > + * - If the page is a normal page, share the existing page > + * > + * In the former case, uses the dev_pagemap_ops migrate_to_ram handler > + * to unmap the device page from QEMU's page tables. > + */ > +static unsigned long > +kvmppc_share_page(struct kvm *kvm, unsigned long gpa, unsigned long page_shift) > +{ > + > + int ret = H_PARAMETER; > + struct page *devm_page; > + struct kvmppc_devm_page_pvt *pvt; > + unsigned long pfn; > + unsigned long *rmap; > + struct kvm_memory_slot *slot; > + unsigned long gfn = gpa >> page_shift; > + int srcu_idx; > + > + srcu_idx = srcu_read_lock(&kvm->srcu); > + slot = gfn_to_memslot(kvm, gfn); > + if (!slot) > + goto out; > + > + rmap = &slot->arch.rmap[gfn - slot->base_gfn]; > + if (kvmppc_rmap_is_devm_pfn(*rmap)) { > + devm_page = pfn_to_page(*rmap & ~KVMPPC_RMAP_DEVM_PFN); > + pvt = (struct kvmppc_devm_page_pvt *) > + devm_page->zone_device_data; > + pvt->skip_page_out = true; > + } > + > + pfn = gfn_to_pfn(kvm, gpa >> page_shift); Use 'gfn'? > + if (is_error_noslot_pfn(pfn)) > + goto out; > + > + ret = uv_page_in(kvm->arch.lpid, pfn << page_shift, gpa, 0, page_shift); > + if (ret == U_SUCCESS) > + ret = H_SUCCESS; > + kvm_release_pfn_clean(pfn); Nit: Blank line? > +out: > + srcu_read_unlock(&kvm->srcu, srcu_idx); > + return ret; > +} > + > /* > * Move page from normal memory to secure memory. > */ > @@ -159,9 +208,12 @@ kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa, > if (page_shift != PAGE_SHIFT) > return H_P3; > > - if (flags) > + if (flags & ~H_PAGE_IN_SHARED) > return H_P2; > > + if (flags & H_PAGE_IN_SHARED) > + return kvmppc_share_page(kvm, gpa, page_shift); > + > ret = H_PARAMETER; > down_read(&kvm->mm->mmap_sem); > srcu_idx = srcu_read_lock(&kvm->srcu); > @@ -211,7 +263,7 @@ kvmppc_devm_fault_migrate_alloc_and_copy(struct migrate_vma *mig, > struct page *dpage, *spage; > struct kvmppc_devm_page_pvt *pvt; > unsigned long pfn; > - int ret; > + int ret = U_SUCCESS; > > spage = migrate_pfn_to_page(*mig->src); > if (!spage || !(*mig->src & MIGRATE_PFN_MIGRATE)) > @@ -226,8 +278,18 @@ kvmppc_devm_fault_migrate_alloc_and_copy(struct migrate_vma *mig, > pvt = spage->zone_device_data; > > pfn = page_to_pfn(dpage); > - ret = uv_page_out(pvt->lpid, pfn << page_shift, pvt->gpa, 0, > - page_shift); > + > + /* > + * This same function is used in two cases: Nit: s/same// > + * - When HV touches a secure page, for which we do page-out Better to qualify page-out with "uv page-out"? its kind of counterintuitive to do a page-out on a fault! > + * - When a secure page is converted to shared page, we touch > + * the page to essentially unmap the device page. In this > + * case we skip page-out. > + */ > + if (!pvt->skip_page_out) > + ret = uv_page_out(pvt->lpid, pfn << page_shift, pvt->gpa, 0, > + page_shift); > + > if (ret == U_SUCCESS) > *mig->dst = migrate_pfn(pfn) | MIGRATE_PFN_LOCKED; > else { > -- > 2.21.0
On Wed, Aug 28, 2019 at 08:04:43PM -0700, Sukadev Bhattiprolu wrote: > > A secure guest will share some of its pages with hypervisor (Eg. virtio > > bounce buffers etc). Support sharing of pages between hypervisor and > > ultravisor. > > > > Once a secure page is converted to shared page, the device page is > > unmapped from the HV side page tables. > > > > Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> > > --- > > arch/powerpc/include/asm/hvcall.h | 3 ++ > > arch/powerpc/kvm/book3s_hv_devm.c | 70 +++++++++++++++++++++++++++++-- > > 2 files changed, 69 insertions(+), 4 deletions(-) > > > > diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h > > index 2f6b952deb0f..05b8536f6653 100644 > > --- a/arch/powerpc/include/asm/hvcall.h > > +++ b/arch/powerpc/include/asm/hvcall.h > > @@ -337,6 +337,9 @@ > > #define H_TLB_INVALIDATE 0xF808 > > #define H_COPY_TOFROM_GUEST 0xF80C > > > > +/* Flags for H_SVM_PAGE_IN */ > > +#define H_PAGE_IN_SHARED 0x1 > > + > > /* Platform-specific hcalls used by the Ultravisor */ > > #define H_SVM_PAGE_IN 0xEF00 > > #define H_SVM_PAGE_OUT 0xEF04 > > diff --git a/arch/powerpc/kvm/book3s_hv_devm.c b/arch/powerpc/kvm/book3s_hv_devm.c > > index 13722f27fa7d..6a3229b78fed 100644 > > --- a/arch/powerpc/kvm/book3s_hv_devm.c > > +++ b/arch/powerpc/kvm/book3s_hv_devm.c > > @@ -46,6 +46,7 @@ struct kvmppc_devm_page_pvt { > > unsigned long *rmap; > > unsigned int lpid; > > unsigned long gpa; > > + bool skip_page_out; > > }; > > > > /* > > @@ -139,6 +140,54 @@ kvmppc_devm_migrate_alloc_and_copy(struct migrate_vma *mig, > > return 0; > > } > > > > +/* > > + * Shares the page with HV, thus making it a normal page. > > + * > > + * - If the page is already secure, then provision a new page and share > > + * - If the page is a normal page, share the existing page > > + * > > + * In the former case, uses the dev_pagemap_ops migrate_to_ram handler > > + * to unmap the device page from QEMU's page tables. > > + */ > > +static unsigned long > > +kvmppc_share_page(struct kvm *kvm, unsigned long gpa, unsigned long page_shift) > > +{ > > + > > + int ret = H_PARAMETER; > > + struct page *devm_page; > > + struct kvmppc_devm_page_pvt *pvt; > > + unsigned long pfn; > > + unsigned long *rmap; > > + struct kvm_memory_slot *slot; > > + unsigned long gfn = gpa >> page_shift; > > + int srcu_idx; > > + > > + srcu_idx = srcu_read_lock(&kvm->srcu); > > + slot = gfn_to_memslot(kvm, gfn); > > + if (!slot) > > + goto out; > > + > > + rmap = &slot->arch.rmap[gfn - slot->base_gfn]; > > + if (kvmppc_rmap_is_devm_pfn(*rmap)) { > > + devm_page = pfn_to_page(*rmap & ~KVMPPC_RMAP_DEVM_PFN); > > + pvt = (struct kvmppc_devm_page_pvt *) > > + devm_page->zone_device_data; > > + pvt->skip_page_out = true; > > + } > > + > > + pfn = gfn_to_pfn(kvm, gpa >> page_shift); > > Use 'gfn'? Yes. > > > + if (is_error_noslot_pfn(pfn)) > > + goto out; > > + > > + ret = uv_page_in(kvm->arch.lpid, pfn << page_shift, gpa, 0, page_shift); > > + if (ret == U_SUCCESS) > > + ret = H_SUCCESS; > > + kvm_release_pfn_clean(pfn); > > Nit: Blank line? > > +out: > > + srcu_read_unlock(&kvm->srcu, srcu_idx); > > + return ret; > > +} > > + > > /* > > * Move page from normal memory to secure memory. > > */ > > @@ -159,9 +208,12 @@ kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa, > > if (page_shift != PAGE_SHIFT) > > return H_P3; > > > > - if (flags) > > + if (flags & ~H_PAGE_IN_SHARED) > > return H_P2; > > > > + if (flags & H_PAGE_IN_SHARED) > > + return kvmppc_share_page(kvm, gpa, page_shift); > > + > > ret = H_PARAMETER; > > down_read(&kvm->mm->mmap_sem); > > srcu_idx = srcu_read_lock(&kvm->srcu); > > @@ -211,7 +263,7 @@ kvmppc_devm_fault_migrate_alloc_and_copy(struct migrate_vma *mig, > > struct page *dpage, *spage; > > struct kvmppc_devm_page_pvt *pvt; > > unsigned long pfn; > > - int ret; > > + int ret = U_SUCCESS; > > > > spage = migrate_pfn_to_page(*mig->src); > > if (!spage || !(*mig->src & MIGRATE_PFN_MIGRATE)) > > @@ -226,8 +278,18 @@ kvmppc_devm_fault_migrate_alloc_and_copy(struct migrate_vma *mig, > > pvt = spage->zone_device_data; > > > > pfn = page_to_pfn(dpage); > > - ret = uv_page_out(pvt->lpid, pfn << page_shift, pvt->gpa, 0, > > - page_shift); > > + > > + /* > > + * This same function is used in two cases: > > Nit: s/same// Extra emphasis :) > > > + * - When HV touches a secure page, for which we do page-out > > Better to qualify page-out with "uv page-out"? its kind of counterintuitive > to do a page-out on a fault! Sure. Regards, Bharata.
diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h index 2f6b952deb0f..05b8536f6653 100644 --- a/arch/powerpc/include/asm/hvcall.h +++ b/arch/powerpc/include/asm/hvcall.h @@ -337,6 +337,9 @@ #define H_TLB_INVALIDATE 0xF808 #define H_COPY_TOFROM_GUEST 0xF80C +/* Flags for H_SVM_PAGE_IN */ +#define H_PAGE_IN_SHARED 0x1 + /* Platform-specific hcalls used by the Ultravisor */ #define H_SVM_PAGE_IN 0xEF00 #define H_SVM_PAGE_OUT 0xEF04 diff --git a/arch/powerpc/kvm/book3s_hv_devm.c b/arch/powerpc/kvm/book3s_hv_devm.c index 13722f27fa7d..6a3229b78fed 100644 --- a/arch/powerpc/kvm/book3s_hv_devm.c +++ b/arch/powerpc/kvm/book3s_hv_devm.c @@ -46,6 +46,7 @@ struct kvmppc_devm_page_pvt { unsigned long *rmap; unsigned int lpid; unsigned long gpa; + bool skip_page_out; }; /* @@ -139,6 +140,54 @@ kvmppc_devm_migrate_alloc_and_copy(struct migrate_vma *mig, return 0; } +/* + * Shares the page with HV, thus making it a normal page. + * + * - If the page is already secure, then provision a new page and share + * - If the page is a normal page, share the existing page + * + * In the former case, uses the dev_pagemap_ops migrate_to_ram handler + * to unmap the device page from QEMU's page tables. + */ +static unsigned long +kvmppc_share_page(struct kvm *kvm, unsigned long gpa, unsigned long page_shift) +{ + + int ret = H_PARAMETER; + struct page *devm_page; + struct kvmppc_devm_page_pvt *pvt; + unsigned long pfn; + unsigned long *rmap; + struct kvm_memory_slot *slot; + unsigned long gfn = gpa >> page_shift; + int srcu_idx; + + srcu_idx = srcu_read_lock(&kvm->srcu); + slot = gfn_to_memslot(kvm, gfn); + if (!slot) + goto out; + + rmap = &slot->arch.rmap[gfn - slot->base_gfn]; + if (kvmppc_rmap_is_devm_pfn(*rmap)) { + devm_page = pfn_to_page(*rmap & ~KVMPPC_RMAP_DEVM_PFN); + pvt = (struct kvmppc_devm_page_pvt *) + devm_page->zone_device_data; + pvt->skip_page_out = true; + } + + pfn = gfn_to_pfn(kvm, gpa >> page_shift); + if (is_error_noslot_pfn(pfn)) + goto out; + + ret = uv_page_in(kvm->arch.lpid, pfn << page_shift, gpa, 0, page_shift); + if (ret == U_SUCCESS) + ret = H_SUCCESS; + kvm_release_pfn_clean(pfn); +out: + srcu_read_unlock(&kvm->srcu, srcu_idx); + return ret; +} + /* * Move page from normal memory to secure memory. */ @@ -159,9 +208,12 @@ kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa, if (page_shift != PAGE_SHIFT) return H_P3; - if (flags) + if (flags & ~H_PAGE_IN_SHARED) return H_P2; + if (flags & H_PAGE_IN_SHARED) + return kvmppc_share_page(kvm, gpa, page_shift); + ret = H_PARAMETER; down_read(&kvm->mm->mmap_sem); srcu_idx = srcu_read_lock(&kvm->srcu); @@ -211,7 +263,7 @@ kvmppc_devm_fault_migrate_alloc_and_copy(struct migrate_vma *mig, struct page *dpage, *spage; struct kvmppc_devm_page_pvt *pvt; unsigned long pfn; - int ret; + int ret = U_SUCCESS; spage = migrate_pfn_to_page(*mig->src); if (!spage || !(*mig->src & MIGRATE_PFN_MIGRATE)) @@ -226,8 +278,18 @@ kvmppc_devm_fault_migrate_alloc_and_copy(struct migrate_vma *mig, pvt = spage->zone_device_data; pfn = page_to_pfn(dpage); - ret = uv_page_out(pvt->lpid, pfn << page_shift, pvt->gpa, 0, - page_shift); + + /* + * This same function is used in two cases: + * - When HV touches a secure page, for which we do page-out + * - When a secure page is converted to shared page, we touch + * the page to essentially unmap the device page. In this + * case we skip page-out. + */ + if (!pvt->skip_page_out) + ret = uv_page_out(pvt->lpid, pfn << page_shift, pvt->gpa, 0, + page_shift); + if (ret == U_SUCCESS) *mig->dst = migrate_pfn(pfn) | MIGRATE_PFN_LOCKED; else {
A secure guest will share some of its pages with hypervisor (Eg. virtio bounce buffers etc). Support sharing of pages between hypervisor and ultravisor. Once a secure page is converted to shared page, the device page is unmapped from the HV side page tables. Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> --- arch/powerpc/include/asm/hvcall.h | 3 ++ arch/powerpc/kvm/book3s_hv_devm.c | 70 +++++++++++++++++++++++++++++-- 2 files changed, 69 insertions(+), 4 deletions(-)