[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Ping: [PATCH V8] x86/altp2m: Hypercall to set altp2m view visibility
Hi, I need a review for the tools bits in this patch. Thanks, Alex On 13.04.2020 09:51, Alexandru Isaila wrote: At this moment a guest can call vmfunc to change the altp2m view. This should be limited in order to avoid any unwanted view switch. The new xc_altp2m_set_visibility() solves this by making views invisible to vmfunc. This is done by having a separate arch.altp2m_working_eptp that is populated and made invalid in the same places as altp2m_eptp. This is written to EPTP_LIST_ADDR. The views are made in/visible by marking them with INVALID_MFN or copying them back from altp2m_eptp. To have consistency the visibility also applies to p2m_switch_domain_altp2m_by_id(). The usage of this hypercall is aimed at dom0 having a logic with a number of views created and at some time there is a need to be sure that only some of the views can be switched, saving the rest and making them visible when the time is right. Note: If altp2m mode is set to mixed the guest is able to change the view visibility and then call vmfunc. Signed-off-by: Alexandru Isaila <aisaila@xxxxxxxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx> --- CC: Ian Jackson <ian.jackson@xxxxxxxxxxxxx> CC: Wei Liu <wl@xxxxxxx> CC: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CC: George Dunlap <George.Dunlap@xxxxxxxxxxxxx> CC: Jan Beulich <jbeulich@xxxxxxxx> CC: Julien Grall <julien@xxxxxxx> CC: Stefano Stabellini <sstabellini@xxxxxxxxxx> CC: "Roger Pau Monné" <roger.pau@xxxxxxxxxx> CC: Jun Nakajima <jun.nakajima@xxxxxxxxx> CC: Kevin Tian <kevin.tian@xxxxxxxxx> --- Changes since V7: - Change altp2m_working_eptp to altp2m_visible_eptp - Rebase. Changes since V6: - Update commit message. Changes since V5: - Change idx type from uint16_t to unsigned int - Add rc var and dropped the err return from p2m_get_suppress_ve(). Changes since V4: - Move p2m specific things from hvm to p2m.c - Add comment for altp2m_idx bounds check - Add altp2m_list_lock/unlock(). Changes since V3: - Change var name form altp2m_idx to idx to shorten line length - Add bounds check for idx - Update commit message - Add comment in xenctrl.h. Changes since V2: - Drop hap_enabled() check - Reduce the indentation depth in hvm.c - Fix assignment indentation - Drop pad2. Changes since V1: - Drop double view from title. --- tools/libxc/include/xenctrl.h | 7 +++++++ tools/libxc/xc_altp2m.c | 24 +++++++++++++++++++++++ xen/arch/x86/hvm/hvm.c | 14 ++++++++++++++ xen/arch/x86/hvm/vmx/vmx.c | 2 +- xen/arch/x86/mm/hap/hap.c | 15 +++++++++++++++ xen/arch/x86/mm/p2m-ept.c | 1 + xen/arch/x86/mm/p2m.c | 34 +++++++++++++++++++++++++++++++-- xen/include/asm-x86/domain.h | 1 + xen/include/asm-x86/p2m.h | 4 ++++ xen/include/public/hvm/hvm_op.h | 9 +++++++++ 10 files changed, 108 insertions(+), 3 deletions(-) diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h index 58fa931de1..5f25c5a6d4 100644 --- a/tools/libxc/include/xenctrl.h +++ b/tools/libxc/include/xenctrl.h @@ -1943,6 +1943,13 @@ int xc_altp2m_change_gfn(xc_interface *handle, uint32_t domid, xen_pfn_t new_gfn); int xc_altp2m_get_vcpu_p2m_idx(xc_interface *handle, uint32_t domid, uint32_t vcpuid, uint16_t *p2midx); +/* + * Set view visibility for xc_altp2m_switch_to_view and vmfunc. + * Note: If altp2m mode is set to mixed the guest is able to change the view + * visibility and then call vmfunc. + */ +int xc_altp2m_set_visibility(xc_interface *handle, uint32_t domid, + uint16_t view_id, bool visible);/*** Mem paging operations. diff --git a/tools/libxc/xc_altp2m.c b/tools/libxc/xc_altp2m.c index 46fb725806..6987c9541f 100644 --- a/tools/libxc/xc_altp2m.c +++ b/tools/libxc/xc_altp2m.c @@ -410,3 +410,27 @@ int xc_altp2m_get_vcpu_p2m_idx(xc_interface *handle, uint32_t domid, xc_hypercall_buffer_free(handle, arg); return rc; } + +int xc_altp2m_set_visibility(xc_interface *handle, uint32_t domid, + uint16_t view_id, bool visible) +{ + int rc; + + DECLARE_HYPERCALL_BUFFER(xen_hvm_altp2m_op_t, arg); + + arg = xc_hypercall_buffer_alloc(handle, arg, sizeof(*arg)); + if ( arg == NULL ) + return -1; + + arg->version = HVMOP_ALTP2M_INTERFACE_VERSION; + arg->cmd = HVMOP_altp2m_set_visibility; + arg->domain = domid; + arg->u.set_visibility.altp2m_idx = view_id; + arg->u.set_visibility.visible = visible; + + rc = xencall2(handle->xcall, __HYPERVISOR_hvm_op, HVMOP_altp2m, + HYPERCALL_BUFFER_AS_ARG(arg)); + + xc_hypercall_buffer_free(handle, arg); + return rc; +} diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 827c5fa89d..6f6f3f73a8 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -4509,6 +4509,7 @@ static int do_altp2m_op( case HVMOP_altp2m_get_mem_access: case HVMOP_altp2m_change_gfn: case HVMOP_altp2m_get_p2m_idx: + case HVMOP_altp2m_set_visibility: break;default:@@ -4786,6 +4787,19 @@ static int do_altp2m_op( break; }+ case HVMOP_altp2m_set_visibility:+ { + unsigned int idx = a.u.set_visibility.altp2m_idx; + + if ( a.u.set_visibility.pad ) + rc = -EINVAL; + else if ( !altp2m_active(d) ) + rc = -EOPNOTSUPP; + else + rc = p2m_set_altp2m_view_visibility(d, idx, + a.u.set_visibility.visible); + } + default: ASSERT_UNREACHABLE(); } diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index 1c398fdb6e..869339062b 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -2140,7 +2140,7 @@ static void vmx_vcpu_update_vmfunc_ve(struct vcpu *v) { v->arch.hvm.vmx.secondary_exec_control |= mask; __vmwrite(VM_FUNCTION_CONTROL, VMX_VMFUNC_EPTP_SWITCHING); - __vmwrite(EPTP_LIST_ADDR, virt_to_maddr(d->arch.altp2m_eptp)); + __vmwrite(EPTP_LIST_ADDR, virt_to_maddr(d->arch.altp2m_visible_eptp));if ( cpu_has_vmx_virt_exceptions ){ diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c index 814d0c3253..052ae35c6f 100644 --- a/xen/arch/x86/mm/hap/hap.c +++ b/xen/arch/x86/mm/hap/hap.c @@ -492,8 +492,17 @@ int hap_enable(struct domain *d, u32 mode) goto out; }+ if ( (d->arch.altp2m_visible_eptp = alloc_xenheap_page()) == NULL )+ { + rv = -ENOMEM; + goto out; + } + for ( i = 0; i < MAX_EPTP; i++ ) + { d->arch.altp2m_eptp[i] = mfn_x(INVALID_MFN); + d->arch.altp2m_visible_eptp[i] = mfn_x(INVALID_MFN); + }for ( i = 0; i < MAX_ALTP2M; i++ ){ @@ -527,6 +536,12 @@ void hap_final_teardown(struct domain *d) d->arch.altp2m_eptp = NULL; }+ if ( d->arch.altp2m_visible_eptp )+ { + free_xenheap_page(d->arch.altp2m_visible_eptp); + d->arch.altp2m_visible_eptp = NULL; + } + for ( i = 0; i < MAX_ALTP2M; i++ ) p2m_teardown(d->arch.altp2m_p2m[i]); } diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c index eb0f0edfef..293f3e9419 100644 --- a/xen/arch/x86/mm/p2m-ept.c +++ b/xen/arch/x86/mm/p2m-ept.c @@ -1368,6 +1368,7 @@ void p2m_init_altp2m_ept(struct domain *d, unsigned int i) ept = &p2m->ept; ept->mfn = pagetable_get_pfn(p2m_get_pagetable(p2m)); d->arch.altp2m_eptp[array_index_nospec(i, MAX_EPTP)] = ept->eptp; + d->arch.altp2m_visible_eptp[array_index_nospec(i, MAX_EPTP)] = ept->eptp; }unsigned int p2m_find_altp2m_by_eptp(struct domain *d, uint64_t eptp)diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c index b8727e267d..4c1507d3a4 100644 --- a/xen/arch/x86/mm/p2m.c +++ b/xen/arch/x86/mm/p2m.c @@ -2533,6 +2533,7 @@ void p2m_flush_altp2m(struct domain *d) { p2m_reset_altp2m(d, i, ALTP2M_DEACTIVATE); d->arch.altp2m_eptp[i] = mfn_x(INVALID_MFN); + d->arch.altp2m_visible_eptp[i] = mfn_x(INVALID_MFN); }altp2m_list_unlock(d);@@ -2652,7 +2653,9 @@ int p2m_destroy_altp2m_by_id(struct domain *d, unsigned int idx) { p2m_reset_altp2m(d, idx, ALTP2M_DEACTIVATE); d->arch.altp2m_eptp[array_index_nospec(idx, MAX_EPTP)] = - mfn_x(INVALID_MFN); + mfn_x(INVALID_MFN); + d->arch.altp2m_visible_eptp[array_index_nospec(idx, MAX_EPTP)] = + mfn_x(INVALID_MFN); rc = 0; } } @@ -2679,7 +2682,7 @@ int p2m_switch_domain_altp2m_by_id(struct domain *d, unsigned int idx) rc = -EINVAL; altp2m_list_lock(d);- if ( d->arch.altp2m_eptp[idx] != mfn_x(INVALID_MFN) )+ if ( d->arch.altp2m_visible_eptp[idx] != mfn_x(INVALID_MFN) ) { for_each_vcpu( d, v ) if ( idx != vcpu_altp2m(v).p2midx ) @@ -3163,6 +3166,33 @@ int p2m_get_suppress_ve(struct domain *d, gfn_t gfn, bool *suppress_ve,return rc;} + +int p2m_set_altp2m_view_visibility(struct domain *d, unsigned int altp2m_idx, + uint8_t visible) +{ + int rc = 0; + + altp2m_list_lock(d); + + /* + * Eptp index is correlated with altp2m index and should not exceed + * min(MAX_ALTP2M, MAX_EPTP). + */ + if ( altp2m_idx >= min(ARRAY_SIZE(d->arch.altp2m_p2m), MAX_EPTP) || + d->arch.altp2m_eptp[array_index_nospec(altp2m_idx, MAX_EPTP)] == + mfn_x(INVALID_MFN) ) + rc = -EINVAL; + else if ( visible ) + d->arch.altp2m_visible_eptp[array_index_nospec(altp2m_idx, MAX_EPTP)] = + d->arch.altp2m_eptp[array_index_nospec(altp2m_idx, MAX_EPTP)]; + else + d->arch.altp2m_visible_eptp[array_index_nospec(altp2m_idx, MAX_EPTP)] = + mfn_x(INVALID_MFN); + + altp2m_list_unlock(d); + + return rc; +} #endif/*diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h index 105adf96eb..4192c636b1 100644 --- a/xen/include/asm-x86/domain.h +++ b/xen/include/asm-x86/domain.h @@ -327,6 +327,7 @@ struct arch_domain struct p2m_domain *altp2m_p2m[MAX_ALTP2M]; mm_lock_t altp2m_list_lock; uint64_t *altp2m_eptp; + uint64_t *altp2m_visible_eptp; #endif/* NB. protected by d->event_lock and by irq_desc[irq].lock */diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h index a2c6049834..ace3573ae8 100644 --- a/xen/include/asm-x86/p2m.h +++ b/xen/include/asm-x86/p2m.h @@ -898,6 +898,10 @@ int p2m_change_altp2m_gfn(struct domain *d, unsigned int idx, int p2m_altp2m_propagate_change(struct domain *d, gfn_t gfn, mfn_t mfn, unsigned int page_order, p2m_type_t p2mt, p2m_access_t p2ma); + +/* Set a specific p2m view visibility */ +int p2m_set_altp2m_view_visibility(struct domain *d, unsigned int idx, + uint8_t visible); #else struct p2m_domain *p2m_get_altp2m(struct vcpu *v); static inline void p2m_altp2m_check(struct vcpu *v, uint16_t idx) {} diff --git a/xen/include/public/hvm/hvm_op.h b/xen/include/public/hvm/hvm_op.h index b599d3cbd0..870ec52060 100644 --- a/xen/include/public/hvm/hvm_op.h +++ b/xen/include/public/hvm/hvm_op.h @@ -318,6 +318,12 @@ struct xen_hvm_altp2m_get_vcpu_p2m_idx { uint16_t altp2m_idx; };+struct xen_hvm_altp2m_set_visibility {+ uint16_t altp2m_idx; + uint8_t visible; + uint8_t pad; +}; + struct xen_hvm_altp2m_op { uint32_t version; /* HVMOP_ALTP2M_INTERFACE_VERSION */ uint32_t cmd; @@ -350,6 +356,8 @@ struct xen_hvm_altp2m_op { #define HVMOP_altp2m_get_p2m_idx 14 /* Set the "Supress #VE" bit for a range of pages */ #define HVMOP_altp2m_set_suppress_ve_multi 15 +/* Set visibility for a given altp2m view */ +#define HVMOP_altp2m_set_visibility 16 domid_t domain; uint16_t pad1; uint32_t pad2; @@ -367,6 +375,7 @@ struct xen_hvm_altp2m_op { struct xen_hvm_altp2m_suppress_ve_multi suppress_ve_multi; struct xen_hvm_altp2m_vcpu_disable_notify disable_notify; struct xen_hvm_altp2m_get_vcpu_p2m_idx get_vcpu_p2m_idx; + struct xen_hvm_altp2m_set_visibility set_visibility; uint8_t pad[64]; } u; };
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