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201 lines
5.7 KiB
201 lines
5.7 KiB
x86: make vcpu_reset() preemptible
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... as dropping the old page tables may take significant amounts of
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time.
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This is part of CVE-2013-1918 / XSA-45.
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Signed-off-by: Jan Beulich <jbeulich@suse.com>
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Acked-by: Tim Deegan <tim@xen.org>
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--- a/xen/arch/x86/domain.c
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+++ b/xen/arch/x86/domain.c
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@@ -1051,17 +1051,16 @@ int arch_set_info_guest(
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#undef c
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}
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-void arch_vcpu_reset(struct vcpu *v)
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+int arch_vcpu_reset(struct vcpu *v)
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{
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if ( !is_hvm_vcpu(v) )
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{
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destroy_gdt(v);
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- vcpu_destroy_pagetables(v, 0);
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- }
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- else
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- {
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- vcpu_end_shutdown_deferral(v);
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+ return vcpu_destroy_pagetables(v);
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}
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+
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+ vcpu_end_shutdown_deferral(v);
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+ return 0;
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}
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/*
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@@ -2085,7 +2084,7 @@ int domain_relinquish_resources(struct d
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/* Drop the in-use references to page-table bases. */
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for_each_vcpu ( d, v )
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{
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- ret = vcpu_destroy_pagetables(v, 1);
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+ ret = vcpu_destroy_pagetables(v);
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if ( ret )
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return ret;
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}
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--- a/xen/arch/x86/hvm/hvm.c
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+++ b/xen/arch/x86/hvm/hvm.c
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@@ -3509,8 +3509,11 @@ static void hvm_s3_suspend(struct domain
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for_each_vcpu ( d, v )
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{
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+ int rc;
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+
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vlapic_reset(vcpu_vlapic(v));
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- vcpu_reset(v);
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+ rc = vcpu_reset(v);
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+ ASSERT(!rc);
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}
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vpic_reset(d);
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--- a/xen/arch/x86/hvm/vlapic.c
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+++ b/xen/arch/x86/hvm/vlapic.c
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@@ -252,10 +252,13 @@ static void vlapic_init_sipi_action(unsi
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{
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case APIC_DM_INIT: {
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bool_t fpu_initialised;
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+ int rc;
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+
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domain_lock(target->domain);
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/* Reset necessary VCPU state. This does not include FPU state. */
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fpu_initialised = target->fpu_initialised;
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- vcpu_reset(target);
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+ rc = vcpu_reset(target);
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+ ASSERT(!rc);
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target->fpu_initialised = fpu_initialised;
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vlapic_reset(vcpu_vlapic(target));
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domain_unlock(target->domain);
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--- a/xen/arch/x86/mm.c
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+++ b/xen/arch/x86/mm.c
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@@ -2827,7 +2827,7 @@ static int put_old_guest_table(struct vc
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return rc;
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}
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-int vcpu_destroy_pagetables(struct vcpu *v, bool_t preemptible)
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+int vcpu_destroy_pagetables(struct vcpu *v)
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{
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unsigned long mfn = pagetable_get_pfn(v->arch.guest_table);
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struct page_info *page;
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@@ -2847,7 +2847,7 @@ int vcpu_destroy_pagetables(struct vcpu
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if ( paging_mode_refcounts(v->domain) )
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put_page(page);
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else
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- rc = put_page_and_type_preemptible(page, preemptible);
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+ rc = put_page_and_type_preemptible(page, 1);
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}
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#ifdef __x86_64__
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@@ -2873,7 +2873,7 @@ int vcpu_destroy_pagetables(struct vcpu
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if ( paging_mode_refcounts(v->domain) )
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put_page(page);
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else
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- rc = put_page_and_type_preemptible(page, preemptible);
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+ rc = put_page_and_type_preemptible(page, 1);
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}
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if ( !rc )
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v->arch.guest_table_user = pagetable_null();
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--- a/xen/common/domain.c
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+++ b/xen/common/domain.c
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@@ -779,14 +779,18 @@ void domain_unpause_by_systemcontroller(
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domain_unpause(d);
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}
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-void vcpu_reset(struct vcpu *v)
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+int vcpu_reset(struct vcpu *v)
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{
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struct domain *d = v->domain;
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+ int rc;
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vcpu_pause(v);
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domain_lock(d);
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- arch_vcpu_reset(v);
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+ set_bit(_VPF_in_reset, &v->pause_flags);
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+ rc = arch_vcpu_reset(v);
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+ if ( rc )
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+ goto out_unlock;
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set_bit(_VPF_down, &v->pause_flags);
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@@ -802,9 +806,13 @@ void vcpu_reset(struct vcpu *v)
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#endif
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cpumask_clear(v->cpu_affinity_tmp);
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clear_bit(_VPF_blocked, &v->pause_flags);
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+ clear_bit(_VPF_in_reset, &v->pause_flags);
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+ out_unlock:
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domain_unlock(v->domain);
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vcpu_unpause(v);
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+
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+ return rc;
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}
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--- a/xen/common/domctl.c
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+++ b/xen/common/domctl.c
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@@ -306,8 +306,10 @@ long do_domctl(XEN_GUEST_HANDLE(xen_domc
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if ( guest_handle_is_null(op->u.vcpucontext.ctxt) )
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{
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- vcpu_reset(v);
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- ret = 0;
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+ ret = vcpu_reset(v);
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+ if ( ret == -EAGAIN )
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+ ret = hypercall_create_continuation(
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+ __HYPERVISOR_domctl, "h", u_domctl);
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goto svc_out;
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}
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--- a/xen/include/asm-x86/mm.h
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+++ b/xen/include/asm-x86/mm.h
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@@ -605,7 +605,7 @@ void audit_domains(void);
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int new_guest_cr3(unsigned long pfn);
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void make_cr3(struct vcpu *v, unsigned long mfn);
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void update_cr3(struct vcpu *v);
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-int vcpu_destroy_pagetables(struct vcpu *, bool_t preemptible);
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+int vcpu_destroy_pagetables(struct vcpu *);
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void propagate_page_fault(unsigned long addr, u16 error_code);
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void *do_page_walk(struct vcpu *v, unsigned long addr);
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--- a/xen/include/xen/domain.h
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+++ b/xen/include/xen/domain.h
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@@ -13,7 +13,7 @@ typedef union {
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struct vcpu *alloc_vcpu(
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struct domain *d, unsigned int vcpu_id, unsigned int cpu_id);
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struct vcpu *alloc_dom0_vcpu0(void);
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-void vcpu_reset(struct vcpu *v);
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+int vcpu_reset(struct vcpu *);
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struct xen_domctl_getdomaininfo;
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void getdomaininfo(struct domain *d, struct xen_domctl_getdomaininfo *info);
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@@ -67,7 +67,7 @@ void arch_dump_vcpu_info(struct vcpu *v)
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void arch_dump_domain_info(struct domain *d);
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-void arch_vcpu_reset(struct vcpu *v);
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+int arch_vcpu_reset(struct vcpu *);
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extern spinlock_t vcpu_alloc_lock;
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bool_t domctl_lock_acquire(void);
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--- a/xen/include/xen/sched.h
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+++ b/xen/include/xen/sched.h
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@@ -644,6 +644,9 @@ static inline struct domain *next_domain
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/* VCPU is blocked due to missing mem_sharing ring. */
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#define _VPF_mem_sharing 6
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#define VPF_mem_sharing (1UL<<_VPF_mem_sharing)
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+ /* VCPU is being reset. */
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+#define _VPF_in_reset 7
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+#define VPF_in_reset (1UL<<_VPF_in_reset)
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static inline int vcpu_runnable(struct vcpu *v)
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{
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