[RFC,2,DO,NOT,APPLY] introduce VCPUOP_register_runstate_phys_memory_area hypercall

Message ID	1558721577-13958-1-git-send-email-andrii.anisov@gmail.com (mailing list archive)
State	Superseded
Headers	show Return-Path: <xen-devel-bounces@lists.xenproject.org> From: Andrii Anisov <andrii.anisov@gmail.com> To: Date: Fri, 24 May 2019 21:12:54 +0300 Message-Id: <1558721577-13958-1-git-send-email-andrii.anisov@gmail.com> Subject: [Xen-devel] [PATCH RFC 2] [DO NOT APPLY] introduce VCPUOP_register_runstate_phys_memory_area hypercall Precedence: list Cc: Stefano Stabellini <sstabellini@kernel.org>, Andrii Anisov <andrii_anisov@epam.com>, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>, George Dunlap <George.Dunlap@eu.citrix.com>, Andrew Cooper <andrew.cooper3@citrix.com>, Ian Jackson <ian.jackson@eu.citrix.com>, Tim Deegan <tim@xen.org>, Julien Grall <julien.grall@arm.com>, Jan Beulich <jbeulich@suse.com>, xen-devel@lists.xenproject.org, Wei Liu <wei.liu2@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" <xen-devel-bounces@lists.xenproject.org>
Series	[RFC,2,DO,NOT,APPLY] introduce VCPUOP_register_runstate_phys_memory_area hypercall \| expand [RFC,2,DO,NOT,APPLY] introduce VCPUOP_register_runstate_phys_memory_area hypercall

diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c index a9f7ff5..04c4cff 100644 --- a/xen/arch/arm/domain.c +++ b/xen/arch/arm/domain.c @@ -274,17 +274,15 @@ static void ctxt_switch_to(struct vcpu *n) virt_timer_restore(n); } -/* Update per-VCPU guest runstate shared memory area (if registered). */ -static void update_runstate_area(struct vcpu *v) +static void update_runstate_by_gvaddr(struct vcpu *v) { void __user *guest_handle = NULL; - if ( guest_handle_is_null(runstate_guest(v)) ) - return; + ASSERT(!guest_handle_is_null(runstate_guest_virt(v))); if ( VM_ASSIST(v->domain, runstate_update_flag) ) { - guest_handle = &v->runstate_guest.p->state_entry_time + 1; + guest_handle = &v->runstate_guest.virt.p->state_entry_time + 1; guest_handle--; v->runstate.state_entry_time |= XEN_RUNSTATE_UPDATE; __raw_copy_to_guest(guest_handle, @@ -292,7 +290,7 @@ static void update_runstate_area(struct vcpu *v) smp_wmb(); } - __copy_to_guest(runstate_guest(v), &v->runstate, 1); + __copy_to_guest(runstate_guest_virt(v), &v->runstate, 1); if ( guest_handle ) { @@ -303,6 +301,58 @@ static void update_runstate_area(struct vcpu *v) } } +extern int map_runstate_area(struct vcpu *v, struct vcpu_runstate_info **area); +extern void unmap_runstate_area(struct vcpu_runstate_info *area); + +static void update_runstate_by_gpaddr(struct vcpu *v) +{ + struct vcpu_runstate_info *runstate; + + if ( map_runstate_area(v, &runstate) ) + return; + + if ( VM_ASSIST(v->domain, runstate_update_flag) ) + { + runstate->state_entry_time |= XEN_RUNSTATE_UPDATE; + smp_wmb(); + v->runstate.state_entry_time |= XEN_RUNSTATE_UPDATE; + } + + memcpy(runstate, &v->runstate, sizeof(v->runstate)); + + if ( VM_ASSIST(v->domain, runstate_update_flag) ) + { + runstate->state_entry_time &= ~XEN_RUNSTATE_UPDATE; + smp_wmb(); + v->runstate.state_entry_time &= ~XEN_RUNSTATE_UPDATE; + } + + unmap_runstate_area(runstate); +} + +/* Update per-VCPU guest runstate shared memory area (if registered). */ +static void update_runstate_area(struct vcpu *v) +{ + if ( xchg(&v->runstate_in_use, 1) ) + return; + + switch ( v->runstate_guest_type ) + { + case RUNSTATE_NONE: + break; + + case RUNSTATE_VADDR: + update_runstate_by_gvaddr(v); + break; + + case RUNSTATE_PADDR: + update_runstate_by_gpaddr(v); + break; + } + + xchg(&v->runstate_in_use, 0); +} + static void schedule_tail(struct vcpu *prev) { ctxt_switch_from(prev); @@ -998,6 +1048,7 @@ long do_arm_vcpu_op(int cmd, unsigned int vcpuid, XEN_GUEST_HANDLE_PARAM(void) a { case VCPUOP_register_vcpu_info: case VCPUOP_register_runstate_memory_area: + case VCPUOP_register_runstate_phys_memory_area: return do_vcpu_op(cmd, vcpuid, arg); default: return -EINVAL; diff --git a/xen/common/domain.c b/xen/common/domain.c index 32bca8d..f167a68 100644 --- a/xen/common/domain.c +++ b/xen/common/domain.c @@ -700,6 +700,68 @@ int rcu_lock_live_remote_domain_by_id(domid_t dom, struct domain **d) return 0; } +void unmap_runstate_area(struct vcpu_runstate_info *area) +{ + mfn_t mfn; + + ASSERT(area != NULL); + + mfn = _mfn(domain_page_map_to_mfn(area)); + + unmap_domain_page_global((void *) + ((unsigned long)area & + PAGE_MASK)); + + put_page_and_type(mfn_to_page(mfn)); +} + +int map_runstate_area(struct vcpu *v, struct vcpu_runstate_info **area) +{ + unsigned long offset = v->runstate_guest.phys & ~PAGE_MASK; + gfn_t gfn = gaddr_to_gfn(v->runstate_guest.phys); + struct domain *d = v->domain; + void *mapping; + struct page_info *page; + size_t size = sizeof(struct vcpu_runstate_info); + + if ( offset > (PAGE_SIZE - size) ) + return -EINVAL; + + page = get_page_from_gfn(d, gfn_x(gfn), NULL, P2M_ALLOC); + if ( !page ) + return -EINVAL; + + if ( !get_page_type(page, PGT_writable_page) ) + { + put_page(page); + return -EINVAL; + } + + mapping = __map_domain_page_global(page); + + if ( mapping == NULL ) + { + put_page_and_type(page); + return -ENOMEM; + } + + *area = mapping + offset; + + return 0; +} + +static void discard_runstate_area(struct vcpu *v) +{ + v->runstate_guest_type = RUNSTATE_NONE; +} + +static void discard_runstate_area_locked(struct vcpu *v) +{ + while ( xchg(&v->runstate_in_use, 1) ); + discard_runstate_area(v); + xchg(&v->runstate_in_use, 0); +} + int domain_kill(struct domain *d) { int rc = 0; @@ -738,7 +800,10 @@ int domain_kill(struct domain *d) if ( cpupool_move_domain(d, cpupool0) ) return -ERESTART; for_each_vcpu ( d, v ) + { + discard_runstate_area_locked(v); unmap_vcpu_info(v); + } d->is_dying = DOMDYING_dead; /* Mem event cleanup has to go here because the rings * have to be put before we call put_domain. */ @@ -1192,7 +1257,7 @@ int domain_soft_reset(struct domain *d) for_each_vcpu ( d, v ) { - set_xen_guest_handle(runstate_guest(v), NULL); + discard_runstate_area_locked(v); unmap_vcpu_info(v); } @@ -1520,18 +1585,46 @@ long do_vcpu_op(int cmd, unsigned int vcpuid, XEN_GUEST_HANDLE_PARAM(void) arg) break; rc = 0; - runstate_guest(v) = area.addr.h; + + while( xchg(&v->runstate_in_use, 1) == 0); + + discard_runstate_area(v); + + runstate_guest_virt(v) = area.addr.h; + v->runstate_guest_type = RUNSTATE_VADDR; if ( v == current ) { - __copy_to_guest(runstate_guest(v), &v->runstate, 1); + __copy_to_guest(runstate_guest_virt(v), &v->runstate, 1); } else { vcpu_runstate_get(v, &runstate); - __copy_to_guest(runstate_guest(v), &runstate, 1); + __copy_to_guest(runstate_guest_virt(v), &runstate, 1); } + xchg(&v->runstate_in_use, 0); + + break; + } + + case VCPUOP_register_runstate_phys_memory_area: + { + struct vcpu_register_runstate_memory_area area; + + rc = -EFAULT; + if ( copy_from_guest(&area, arg, 1) ) + break; + + while( xchg(&v->runstate_in_use, 1) == 0); + + discard_runstate_area(v); + v->runstate_guest.phys = area.addr.p; + v->runstate_guest_type = RUNSTATE_PADDR; + + xchg(&v->runstate_in_use, 0); + rc = 0; + break; } diff --git a/xen/include/public/vcpu.h b/xen/include/public/vcpu.h index 3623af9..d7da4a3 100644 --- a/xen/include/public/vcpu.h +++ b/xen/include/public/vcpu.h @@ -235,6 +235,21 @@ struct vcpu_register_time_memory_area { typedef struct vcpu_register_time_memory_area vcpu_register_time_memory_area_t; DEFINE_XEN_GUEST_HANDLE(vcpu_register_time_memory_area_t); +/* + * Register a shared memory area from which the guest may obtain its own + * runstate information without needing to execute a hypercall. + * Notes: + * 1. The registered address must be guest's physical address. + * 2. The registered runstate area should not cross page boundary. + * 3. Only one shared area may be registered per VCPU. The shared area is + * updated by the hypervisor each time the VCPU is scheduled. Thus + * runstate.state will always be RUNSTATE_running and + * runstate.state_entry_time will indicate the system time at which the + * VCPU was last scheduled to run. + * @extra_arg == pointer to vcpu_register_runstate_memory_area structure. + */ +#define VCPUOP_register_runstate_phys_memory_area 14 + #endif /* __XEN_PUBLIC_VCPU_H__ */ /* diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h index edee52d..8ac597b 100644 --- a/xen/include/xen/sched.h +++ b/xen/include/xen/sched.h @@ -163,17 +163,31 @@ struct vcpu void *sched_priv; /* scheduler-specific data */ struct vcpu_runstate_info runstate; + + enum { + RUNSTATE_NONE = 0, + RUNSTATE_PADDR = 1, + RUNSTATE_VADDR = 2, + } runstate_guest_type; + + unsigned long runstate_in_use; + + union + { #ifndef CONFIG_COMPAT -# define runstate_guest(v) ((v)->runstate_guest) - XEN_GUEST_HANDLE(vcpu_runstate_info_t) runstate_guest; /* guest address */ +# define runstate_guest_virt(v) ((v)->runstate_guest.virt) + XEN_GUEST_HANDLE(vcpu_runstate_info_t) virt; /* guest address */ #else -# define runstate_guest(v) ((v)->runstate_guest.native) - union { - XEN_GUEST_HANDLE(vcpu_runstate_info_t) native; - XEN_GUEST_HANDLE(vcpu_runstate_info_compat_t) compat; - } runstate_guest; /* guest address */ +# define runstate_guest_virt(v) ((v)->runstate_guest.virt.native) + union { + XEN_GUEST_HANDLE(vcpu_runstate_info_t) native; + XEN_GUEST_HANDLE(vcpu_runstate_info_compat_t) compat; + } virt; /* guest address */ #endif + paddr_t phys; + } runstate_guest; + /* last time when vCPU is scheduled out */ uint64_t last_run_time;

[RFC,2,DO,NOT,APPLY] introduce VCPUOP_register_runstate_phys_memory_area hypercall

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