* [Xen-devel] [PATCH v13 0/3] VM forking
@ 2020-03-30 15:02 Tamas K Lengyel
2020-03-30 15:02 ` [Xen-devel] [PATCH v13 1/3] xen/mem_sharing: " Tamas K Lengyel
` (2 more replies)
0 siblings, 3 replies; 7+ messages in thread
From: Tamas K Lengyel @ 2020-03-30 15:02 UTC (permalink / raw)
To: xen-devel
Cc: Stefano Stabellini, Tamas K Lengyel, Wei Liu, Andrew Cooper,
Ian Jackson, George Dunlap, Tamas K Lengyel, Jan Beulich,
Anthony PERARD, Julien Grall, Volodymyr Babchuk,
Roger Pau Monné
The following series implements VM forking for Intel HVM guests to allow for
the fast creation of identical VMs without the assosciated high startup costs
of booting or restoring the VM from a savefile.
JIRA issue: https://xenproject.atlassian.net/browse/XEN-89
The fork operation is implemented as part of the "xl fork-vm" command:
xl fork-vm -C <config> -Q <qemu-save-file> -m <max-vcpus> <parent_domid>
By default a fully functional fork is created. The user is in charge however to
create the appropriate config file for the fork and to generate the QEMU save
file before the fork-vm call is made. The config file needs to give the
fork a new name at minimum but other settings may also require changes. Certain
settings in the config file of both the parent and the fork have to be set to
default. Details are documented.
The interface also allows to split the forking into two steps:
xl fork-vm --launch-dm no \
-m <max-vcpus> \
-p <parent_domid>
xl fork-vm --launch-dm late \
-C <config_file_for_fork> \
-Q <qemu_save_file> \
<fork_domid>
The split creation model is useful when the VM needs to be created as fast as
possible. The forked VM can be unpaused without the device model being launched
to be monitored and accessed via VMI. Note however that without its device
model running (depending on what is executing in the VM) it is bound to
misbehave or even crash when its trying to access devices that would be
emulated by QEMU. We anticipate that for certain use-cases this would be an
acceptable situation, in case for example when fuzzing is performed of code
segments that don't access such devices.
Launching the device model requires the QEMU Xen savefile to be generated
manually from the parent VM. This can be accomplished simply by connecting to
its QMP socket and issuing the "xen-save-devices-state" command. For example
using the standard tool socat these commands can be used to generate the file:
socat - UNIX-CONNECT:/var/run/xen/qmp-libxl-<parent_domid>
{ "execute": "qmp_capabilities" }
{ "execute": "xen-save-devices-state", \
"arguments": { "filename": "/path/to/save/qemu_state", \
"live": false} }
At runtime the forked VM starts running with an empty p2m which gets lazily
populated when the VM generates EPT faults, similar to how altp2m views are
populated. If the memory access is a read-only access, the p2m entry is
populated with a memory shared entry with its parent. For write memory accesses
or in case memory sharing wasn't possible (for example in case a reference is
held by a third party), a new page is allocated and the page contents are
copied over from the parent VM. Forks can be further forked if needed, thus
allowing for further memory savings.
A VM fork reset hypercall is also added that allows the fork to be reset to the
state it was just after a fork, also accessible via xl:
xl fork-vm --fork-reset -p <fork_domid>
This is an optimization for cases where the forks are very short-lived and run
without a device model, so resetting saves some time compared to creating a
brand new fork provided the fork has not aquired a lot of memory. If the fork
has a lot of memory deduplicated it is likely going to be faster to create a
new fork from scratch and asynchronously destroying the old one.
The series has been tested with Windows VMs and functions as expected. Linux
VMs when forked from a running VM will have a frozen VNC screen. Linux VMs at
this time can only be forked with a working device model when the parent VM was
restored from a snapshot using "xl restore -p". This is a known limitation.
Also note that PVHVM/PVH Linux guests have not been tested. Forking most likely
works but PV devices and drivers would require additional wiring to set things
up properly since the guests are unaware of the forking taking place, unlike
the save/restore routine where the guest is made aware of the procedure.
Forking time has been measured to be 0.0007s, device model launch to be around
1s depending largely on the number of devices being emulated. Fork resets have
been measured to be 0.0001s under the optimal circumstances.
New in v13:
style cleanups & minor adjustments
Introduce and use PAGE_OFFSET macro
Patch 1 implements the VM fork
Patch 2 implements fork reset operation
Patch 3 adds the toolstack-side code implementing VM forking and reset
Tamas K Lengyel (3):
xen/mem_sharing: VM forking
x86/mem_sharing: reset a fork
xen/tools: VM forking toolstack side
docs/man/xl.1.pod.in | 44 +++
tools/libxc/include/xenctrl.h | 13 +
tools/libxc/xc_memshr.c | 22 ++
tools/libxl/libxl.h | 11 +
tools/libxl/libxl_create.c | 361 ++++++++++++++-----------
tools/libxl/libxl_dm.c | 2 +-
tools/libxl/libxl_dom.c | 43 ++-
tools/libxl/libxl_internal.h | 7 +
tools/libxl/libxl_types.idl | 1 +
tools/libxl/libxl_x86.c | 41 +++
tools/xl/Makefile | 2 +-
tools/xl/xl.h | 5 +
tools/xl/xl_cmdtable.c | 15 ++
tools/xl/xl_forkvm.c | 147 ++++++++++
tools/xl/xl_vmcontrol.c | 14 +
xen/arch/x86/domain.c | 13 +
xen/arch/x86/hvm/hvm.c | 4 +-
xen/arch/x86/mm/hap/hap.c | 3 +-
xen/arch/x86/mm/mem_sharing.c | 428 ++++++++++++++++++++++++++++++
xen/arch/x86/mm/p2m.c | 9 +-
xen/include/asm-arm/page.h | 1 +
xen/include/asm-x86/hap.h | 1 +
xen/include/asm-x86/hvm/hvm.h | 2 +
xen/include/asm-x86/mem_sharing.h | 18 ++
xen/include/asm-x86/page.h | 1 +
xen/include/public/memory.h | 6 +
xen/include/xen/sched.h | 1 +
27 files changed, 1044 insertions(+), 171 deletions(-)
create mode 100644 tools/xl/xl_forkvm.c
--
2.20.1
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Xen-devel] [PATCH v13 1/3] xen/mem_sharing: VM forking
2020-03-30 15:02 [Xen-devel] [PATCH v13 0/3] VM forking Tamas K Lengyel
@ 2020-03-30 15:02 ` Tamas K Lengyel
2020-03-31 10:09 ` Julien Grall
2020-04-06 10:52 ` Roger Pau Monné
2020-03-30 15:02 ` [Xen-devel] [PATCH v13 2/3] x86/mem_sharing: reset a fork Tamas K Lengyel
2020-03-30 15:02 ` [Xen-devel] [PATCH v13 3/3] xen/tools: VM forking toolstack side Tamas K Lengyel
2 siblings, 2 replies; 7+ messages in thread
From: Tamas K Lengyel @ 2020-03-30 15:02 UTC (permalink / raw)
To: xen-devel
Cc: Stefano Stabellini, Tamas K Lengyel, Wei Liu, Andrew Cooper,
Ian Jackson, George Dunlap, Tamas K Lengyel, Jan Beulich,
Julien Grall, Volodymyr Babchuk, Roger Pau Monné
VM forking is the process of creating a domain with an empty memory space and a
parent domain specified from which to populate the memory when necessary. For
the new domain to be functional the VM state is copied over as part of the fork
operation (HVM params, hap allocation, etc).
Signed-off-by: Tamas K Lengyel <tamas.lengyel@intel.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
v13: Address issues pointed out by Roger & Jan
Introduce & use PAGE_OFFSET to calculate vcpu_info offset
---
xen/arch/x86/domain.c | 13 ++
xen/arch/x86/hvm/hvm.c | 4 +-
xen/arch/x86/mm/hap/hap.c | 3 +-
xen/arch/x86/mm/mem_sharing.c | 351 ++++++++++++++++++++++++++++++
xen/arch/x86/mm/p2m.c | 9 +-
xen/include/asm-arm/page.h | 1 +
xen/include/asm-x86/hap.h | 1 +
xen/include/asm-x86/hvm/hvm.h | 2 +
xen/include/asm-x86/mem_sharing.h | 18 ++
xen/include/asm-x86/page.h | 1 +
xen/include/public/memory.h | 5 +
xen/include/xen/sched.h | 1 +
12 files changed, 404 insertions(+), 5 deletions(-)
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 683bc619aa..a008d7df1c 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -2211,6 +2211,19 @@ int domain_relinquish_resources(struct domain *d)
ret = relinquish_shared_pages(d);
if ( ret )
return ret;
+
+ /*
+ * If the domain is forked, decrement the parent's pause count
+ * and release the domain.
+ */
+ if ( mem_sharing_is_fork(d) )
+ {
+ struct domain *parent = d->parent;
+
+ d->parent = NULL;
+ domain_unpause(parent);
+ put_domain(parent);
+ }
}
#endif
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index a3d115b650..304b3d1562 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -1917,7 +1917,7 @@ int hvm_hap_nested_page_fault(paddr_t gpa, unsigned long gla,
}
#endif
- /* Spurious fault? PoD and log-dirty also take this path. */
+ /* Spurious fault? PoD, log-dirty and VM forking also take this path. */
if ( p2m_is_ram(p2mt) )
{
rc = 1;
@@ -4377,7 +4377,7 @@ static int hvm_allow_get_param(struct domain *d,
return rc;
}
-static int hvm_get_param(struct domain *d, uint32_t index, uint64_t *value)
+int hvm_get_param(struct domain *d, uint32_t index, uint64_t *value)
{
int rc;
diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c
index a6d5e39b02..814d0c3253 100644
--- a/xen/arch/x86/mm/hap/hap.c
+++ b/xen/arch/x86/mm/hap/hap.c
@@ -321,8 +321,7 @@ static void hap_free_p2m_page(struct domain *d, struct page_info *pg)
}
/* Return the size of the pool, rounded up to the nearest MB */
-static unsigned int
-hap_get_allocation(struct domain *d)
+unsigned int hap_get_allocation(struct domain *d)
{
unsigned int pg = d->arch.paging.hap.total_pages
+ d->arch.paging.hap.p2m_pages;
diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c
index f49f27a3ef..faa79011c3 100644
--- a/xen/arch/x86/mm/mem_sharing.c
+++ b/xen/arch/x86/mm/mem_sharing.c
@@ -22,6 +22,7 @@
#include <xen/types.h>
#include <xen/domain_page.h>
+#include <xen/event.h>
#include <xen/spinlock.h>
#include <xen/rwlock.h>
#include <xen/mm.h>
@@ -36,6 +37,8 @@
#include <asm/altp2m.h>
#include <asm/atomic.h>
#include <asm/event.h>
+#include <asm/hap.h>
+#include <asm/hvm/hvm.h>
#include <xsm/xsm.h>
#include "mm-locks.h"
@@ -1443,6 +1446,318 @@ static inline int mem_sharing_control(struct domain *d, bool enable)
return 0;
}
+/*
+ * Forking a page only gets called when the VM faults due to no entry being
+ * in the EPT for the access. Depending on the type of access we either
+ * populate the physmap with a shared entry for read-only access or
+ * fork the page if its a write access.
+ *
+ * The client p2m is already locked so we only need to lock
+ * the parent's here.
+ */
+int mem_sharing_fork_page(struct domain *d, gfn_t gfn, bool unsharing)
+{
+ int rc = -ENOENT;
+ shr_handle_t handle;
+ struct domain *parent = d->parent;
+ struct p2m_domain *p2m;
+ unsigned long gfn_l = gfn_x(gfn);
+ mfn_t mfn, new_mfn;
+ p2m_type_t p2mt;
+ struct page_info *page;
+
+ if ( !mem_sharing_is_fork(d) )
+ return -ENOENT;
+
+ if ( !unsharing )
+ {
+ /* For read-only accesses we just add a shared entry to the physmap */
+ while ( parent )
+ {
+ if ( !(rc = nominate_page(parent, gfn, 0, &handle)) )
+ break;
+
+ parent = parent->parent;
+ }
+
+ if ( !rc )
+ {
+ /* The client's p2m is already locked */
+ p2m = p2m_get_hostp2m(parent);
+
+ p2m_lock(p2m);
+ rc = add_to_physmap(parent, gfn_l, handle, d, gfn_l, false);
+ p2m_unlock(p2m);
+
+ if ( !rc )
+ return 0;
+ }
+ }
+
+ /*
+ * If it's a write access (ie. unsharing) or if adding a shared entry to
+ * the physmap failed we'll fork the page directly.
+ */
+ p2m = p2m_get_hostp2m(d);
+ parent = d->parent;
+
+ while ( parent )
+ {
+ mfn = get_gfn_query(parent, gfn_l, &p2mt);
+
+ /* We can't fork grant memory from the parent, only regular ram */
+ if ( mfn_valid(mfn) && p2m_is_ram(p2mt) )
+ break;
+
+ put_gfn(parent, gfn_l);
+ parent = parent->parent;
+ }
+
+ if ( !parent )
+ return -ENOENT;
+
+ if ( !(page = alloc_domheap_page(d, 0)) )
+ {
+ put_gfn(parent, gfn_l);
+ return -ENOMEM;
+ }
+
+ new_mfn = page_to_mfn(page);
+ copy_domain_page(new_mfn, mfn);
+ set_gpfn_from_mfn(mfn_x(new_mfn), gfn_l);
+
+ put_gfn(parent, gfn_l);
+
+ return p2m->set_entry(p2m, gfn, new_mfn, PAGE_ORDER_4K, p2m_ram_rw,
+ p2m->default_access, -1);
+}
+
+static int bring_up_vcpus(struct domain *cd, struct domain *d)
+{
+ unsigned int i;
+ int ret = -EINVAL;
+
+ if ( d->max_vcpus != cd->max_vcpus ||
+ (ret = cpupool_move_domain(cd, d->cpupool)) )
+ return ret;
+
+ for ( i = 0; i < cd->max_vcpus; i++ )
+ {
+ if ( !d->vcpu[i] || cd->vcpu[i] )
+ continue;
+
+ if ( !vcpu_create(cd, i) )
+ return -EINVAL;
+ }
+
+ domain_update_node_affinity(cd);
+ return 0;
+}
+
+static int copy_vcpu_settings(struct domain *cd, struct domain *d)
+{
+ unsigned int i;
+ struct p2m_domain *p2m = p2m_get_hostp2m(cd);
+ int ret = -EINVAL;
+
+ for ( i = 0; i < cd->max_vcpus; i++ )
+ {
+ const struct vcpu *d_vcpu = d->vcpu[i];
+ struct vcpu *cd_vcpu = cd->vcpu[i];
+ struct vcpu_runstate_info runstate;
+ mfn_t vcpu_info_mfn;
+
+ if ( !d_vcpu || !cd_vcpu )
+ continue;
+
+ /* Copy & map in the vcpu_info page if the guest uses one */
+ vcpu_info_mfn = d_vcpu->vcpu_info_mfn;
+ if ( !mfn_eq(vcpu_info_mfn, INVALID_MFN) )
+ {
+ mfn_t new_vcpu_info_mfn = cd_vcpu->vcpu_info_mfn;
+
+ /* Allocate & map the page for it if it hasn't been already */
+ if ( mfn_eq(new_vcpu_info_mfn, INVALID_MFN) )
+ {
+ gfn_t gfn = mfn_to_gfn(d, vcpu_info_mfn);
+ unsigned long gfn_l = gfn_x(gfn);
+ struct page_info *page;
+
+ if ( !(page = alloc_domheap_page(cd, 0)) )
+ return -ENOMEM;
+
+ new_vcpu_info_mfn = page_to_mfn(page);
+ set_gpfn_from_mfn(mfn_x(new_vcpu_info_mfn), gfn_l);
+
+ ret = p2m->set_entry(p2m, gfn, new_vcpu_info_mfn,
+ PAGE_ORDER_4K, p2m_ram_rw,
+ p2m->default_access, -1);
+ if ( ret )
+ return ret;
+
+ ret = map_vcpu_info(cd_vcpu, gfn_l,
+ PAGE_OFFSET(d_vcpu->vcpu_info));
+ if ( ret )
+ return ret;
+ }
+
+ copy_domain_page(new_vcpu_info_mfn, vcpu_info_mfn);
+ }
+
+ /* Setup the vCPU runstate area */
+ if ( !guest_handle_is_null(runstate_guest(d_vcpu)) )
+ {
+ runstate_guest(cd_vcpu) = runstate_guest(d_vcpu);
+ vcpu_runstate_get(cd_vcpu, &runstate);
+ __copy_to_guest(runstate_guest(cd_vcpu), &runstate, 1);
+ }
+
+ /*
+ * TODO: to support VMs with PV interfaces copy additional
+ * settings here, such as PV timers.
+ */
+ }
+
+ return 0;
+}
+
+static int fork_hap_allocation(struct domain *cd, struct domain *d)
+{
+ int rc;
+ bool preempted;
+ unsigned long mb = hap_get_allocation(d);
+
+ if ( mb == hap_get_allocation(cd) )
+ return 0;
+
+ paging_lock(cd);
+ rc = hap_set_allocation(cd, mb << (20 - PAGE_SHIFT), &preempted);
+ paging_unlock(cd);
+
+ return preempted ? -ERESTART : rc;
+}
+
+static void copy_tsc(struct domain *cd, struct domain *d)
+{
+ uint32_t tsc_mode;
+ uint32_t gtsc_khz;
+ uint32_t incarnation;
+ uint64_t elapsed_nsec;
+
+ tsc_get_info(d, &tsc_mode, &elapsed_nsec, >sc_khz, &incarnation);
+ /* Don't bump incarnation on set */
+ tsc_set_info(cd, tsc_mode, elapsed_nsec, gtsc_khz, incarnation - 1);
+}
+
+static int copy_special_pages(struct domain *cd, struct domain *d)
+{
+ mfn_t new_mfn, old_mfn;
+ struct p2m_domain *p2m = p2m_get_hostp2m(cd);
+ static const unsigned int params[] =
+ {
+ HVM_PARAM_STORE_PFN,
+ HVM_PARAM_IOREQ_PFN,
+ HVM_PARAM_BUFIOREQ_PFN,
+ HVM_PARAM_CONSOLE_PFN
+ };
+ unsigned int i;
+ int rc;
+
+ for ( i = 0; i < ARRAY_SIZE(params); i++ )
+ {
+ p2m_type_t t;
+ uint64_t value = 0;
+ struct page_info *page;
+
+ if ( hvm_get_param(cd, params[i], &value) || !value )
+ continue;
+
+ old_mfn = get_gfn_query_unlocked(d, value, &t);
+ new_mfn = get_gfn_query_unlocked(cd, value, &t);
+
+ /* Allocate the page and map it in if it's not present */
+ if ( mfn_eq(new_mfn, INVALID_MFN) )
+ {
+ if ( !(page = alloc_domheap_page(cd, 0)) )
+ return -ENOMEM;
+
+ new_mfn = page_to_mfn(page);
+ set_gpfn_from_mfn(mfn_x(new_mfn), value);
+
+ rc = p2m->set_entry(p2m, _gfn(value), new_mfn, PAGE_ORDER_4K,
+ p2m_ram_rw, p2m->default_access, -1);
+ if ( rc )
+ return rc;
+ }
+
+ copy_domain_page(new_mfn, old_mfn);
+ }
+
+ old_mfn = _mfn(virt_to_mfn(d->shared_info));
+ new_mfn = _mfn(virt_to_mfn(cd->shared_info));
+ copy_domain_page(new_mfn, old_mfn);
+
+ return 0;
+}
+
+static int copy_settings(struct domain *cd, struct domain *d)
+{
+ int rc;
+
+ if ( (rc = copy_vcpu_settings(cd, d)) )
+ return rc;
+
+ if ( (rc = hvm_copy_context_and_params(cd, d)) )
+ return rc;
+
+ if ( (rc = copy_special_pages(cd, d)) )
+ return rc;
+
+ copy_tsc(cd, d);
+
+ return rc;
+}
+
+static int fork(struct domain *cd, struct domain *d)
+{
+ int rc = -EBUSY;
+
+ if ( !cd->controller_pause_count )
+ return rc;
+
+ if ( !cd->parent )
+ {
+ if ( !get_domain(d) )
+ {
+ ASSERT_UNREACHABLE();
+ return -EBUSY;
+ }
+
+ domain_pause(d);
+ cd->max_pages = d->max_pages;
+ cd->parent = d;
+ }
+
+ /* This is preemptible so it's the first to get done */
+ if ( (rc = fork_hap_allocation(cd, d)) )
+ goto done;
+
+ if ( (rc = bring_up_vcpus(cd, d)) )
+ goto done;
+
+ rc = copy_settings(cd, d);
+
+ done:
+ if ( rc && rc != -ERESTART )
+ {
+ domain_unpause(d);
+ put_domain(d);
+ cd->parent = NULL;
+ }
+
+ return rc;
+}
+
int mem_sharing_memop(XEN_GUEST_HANDLE_PARAM(xen_mem_sharing_op_t) arg)
{
int rc;
@@ -1697,6 +2012,42 @@ int mem_sharing_memop(XEN_GUEST_HANDLE_PARAM(xen_mem_sharing_op_t) arg)
rc = debug_gref(d, mso.u.debug.u.gref);
break;
+ case XENMEM_sharing_op_fork:
+ {
+ struct domain *pd;
+
+ rc = -EINVAL;
+ if ( mso.u.fork.pad[0] || mso.u.fork.pad[1] || mso.u.fork.pad[2] )
+ goto out;
+
+ rc = rcu_lock_live_remote_domain_by_id(mso.u.fork.parent_domain,
+ &pd);
+ if ( rc )
+ goto out;
+
+ rc = -EINVAL;
+ if ( pd->max_vcpus != d->max_vcpus )
+ {
+ rcu_unlock_domain(pd);
+ goto out;
+ }
+
+ if ( !mem_sharing_enabled(pd) && (rc = mem_sharing_control(pd, true)) )
+ {
+ rcu_unlock_domain(pd);
+ goto out;
+ }
+
+ rc = fork(d, pd);
+
+ if ( rc == -ERESTART )
+ rc = hypercall_create_continuation(__HYPERVISOR_memory_op,
+ "lh", XENMEM_sharing_op,
+ arg);
+ rcu_unlock_domain(pd);
+ break;
+ }
+
default:
rc = -ENOSYS;
break;
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index d93c418bcf..0d0e34e81e 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -509,6 +509,12 @@ mfn_t __get_gfn_type_access(struct p2m_domain *p2m, unsigned long gfn_l,
mfn = p2m->get_entry(p2m, gfn, t, a, q, page_order, NULL);
+ /* Check if we need to fork the page */
+ if ( (q & P2M_ALLOC) && p2m_is_hole(*t) &&
+ !mem_sharing_fork_page(p2m->domain, gfn, q & P2M_UNSHARE) )
+ mfn = p2m->get_entry(p2m, gfn, t, a, q, page_order, NULL);
+
+ /* Check if we need to unshare the page */
if ( (q & P2M_UNSHARE) && p2m_is_shared(*t) )
{
ASSERT(p2m_is_hostp2m(p2m));
@@ -588,7 +594,8 @@ struct page_info *p2m_get_page_from_gfn(
return page;
/* Error path: not a suitable GFN at all */
- if ( !p2m_is_ram(*t) && !p2m_is_paging(*t) && !p2m_is_pod(*t) )
+ if ( !p2m_is_ram(*t) && !p2m_is_paging(*t) && !p2m_is_pod(*t) &&
+ !mem_sharing_is_fork(p2m->domain) )
return NULL;
}
diff --git a/xen/include/asm-arm/page.h b/xen/include/asm-arm/page.h
index 37e1d9aadb..4ea8e97247 100644
--- a/xen/include/asm-arm/page.h
+++ b/xen/include/asm-arm/page.h
@@ -12,6 +12,7 @@
#define PADDR_BITS 40
#endif
#define PADDR_MASK ((1ULL << PADDR_BITS)-1)
+#define PAGE_OFFSET(ptr) ((vaddr_t)(ptr) & ~PAGE_MASK)
#define VADDR_BITS 32
#define VADDR_MASK (~0UL)
diff --git a/xen/include/asm-x86/hap.h b/xen/include/asm-x86/hap.h
index b94bfb4ed0..1bf07e49fe 100644
--- a/xen/include/asm-x86/hap.h
+++ b/xen/include/asm-x86/hap.h
@@ -45,6 +45,7 @@ int hap_track_dirty_vram(struct domain *d,
extern const struct paging_mode *hap_paging_get_mode(struct vcpu *);
int hap_set_allocation(struct domain *d, unsigned int pages, bool *preempted);
+unsigned int hap_get_allocation(struct domain *d);
#endif /* XEN_HAP_H */
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index b007b2e343..f283c7d187 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -336,6 +336,8 @@ unsigned long hvm_cr4_guest_valid_bits(const struct domain *d, bool restore);
int hvm_copy_context_and_params(struct domain *src, struct domain *dst);
+int hvm_get_param(struct domain *d, uint32_t index, uint64_t *value);
+
#ifdef CONFIG_HVM
#define hvm_get_guest_tsc(v) hvm_get_guest_tsc_fixed(v, 0)
diff --git a/xen/include/asm-x86/mem_sharing.h b/xen/include/asm-x86/mem_sharing.h
index 53b7929d0e..cf7a12f4d2 100644
--- a/xen/include/asm-x86/mem_sharing.h
+++ b/xen/include/asm-x86/mem_sharing.h
@@ -77,6 +77,14 @@ static inline int mem_sharing_unshare_page(struct domain *d,
return rc;
}
+static inline bool mem_sharing_is_fork(const struct domain *d)
+{
+ return d->parent;
+}
+
+int mem_sharing_fork_page(struct domain *d, gfn_t gfn,
+ bool unsharing);
+
/*
* If called by a foreign domain, possible errors are
* -EBUSY -> ring full
@@ -130,6 +138,16 @@ static inline int mem_sharing_notify_enomem(struct domain *d, unsigned long gfn,
return -EOPNOTSUPP;
}
+static inline bool mem_sharing_is_fork(const struct domain *d)
+{
+ return false;
+}
+
+static inline int mem_sharing_fork_page(struct domain *d, gfn_t gfn, bool lock)
+{
+ return -EOPNOTSUPP;
+}
+
#endif
#endif /* __MEM_SHARING_H__ */
diff --git a/xen/include/asm-x86/page.h b/xen/include/asm-x86/page.h
index c98d8f5ede..eb73a0fc23 100644
--- a/xen/include/asm-x86/page.h
+++ b/xen/include/asm-x86/page.h
@@ -10,6 +10,7 @@
#define PAGE_SIZE (_AC(1,L) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
#define PAGE_FLAG_MASK (~0)
+#define PAGE_OFFSET(ptr) ((unsigned long)(ptr) & ~PAGE_MASK)
#define PAGE_ORDER_4K 0
#define PAGE_ORDER_2M 9
diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
index 126d0ff06e..5ee4e0da12 100644
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -482,6 +482,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_mem_access_op_t);
#define XENMEM_sharing_op_add_physmap 6
#define XENMEM_sharing_op_audit 7
#define XENMEM_sharing_op_range_share 8
+#define XENMEM_sharing_op_fork 9
#define XENMEM_SHARING_OP_S_HANDLE_INVALID (-10)
#define XENMEM_SHARING_OP_C_HANDLE_INVALID (-9)
@@ -532,6 +533,10 @@ struct xen_mem_sharing_op {
uint32_t gref; /* IN: gref to debug */
} u;
} debug;
+ struct mem_sharing_op_fork { /* OP_FORK */
+ domid_t parent_domain; /* IN: parent's domain id */
+ uint16_t pad[3]; /* Must be set to 0 */
+ } fork;
} u;
};
typedef struct xen_mem_sharing_op xen_mem_sharing_op_t;
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 4b78291d51..195e7ee583 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -481,6 +481,7 @@ struct domain
/* Memory sharing support */
#ifdef CONFIG_MEM_SHARING
struct vm_event_domain *vm_event_share;
+ struct domain *parent; /* VM fork parent */
#endif
/* Memory paging support */
#ifdef CONFIG_HAS_MEM_PAGING
--
2.20.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [Xen-devel] [PATCH v13 2/3] x86/mem_sharing: reset a fork
2020-03-30 15:02 [Xen-devel] [PATCH v13 0/3] VM forking Tamas K Lengyel
2020-03-30 15:02 ` [Xen-devel] [PATCH v13 1/3] xen/mem_sharing: " Tamas K Lengyel
@ 2020-03-30 15:02 ` Tamas K Lengyel
2020-03-30 15:02 ` [Xen-devel] [PATCH v13 3/3] xen/tools: VM forking toolstack side Tamas K Lengyel
2 siblings, 0 replies; 7+ messages in thread
From: Tamas K Lengyel @ 2020-03-30 15:02 UTC (permalink / raw)
To: xen-devel
Cc: Tamas K Lengyel, Tamas K Lengyel, Wei Liu, Andrew Cooper,
Ian Jackson, George Dunlap, Stefano Stabellini, Jan Beulich,
Julien Grall, Roger Pau Monné
Implement hypercall that allows a fork to shed all memory that got allocated
for it during its execution and re-load its vCPU context from the parent VM.
This allows the forked VM to reset into the same state the parent VM is in a
faster way then creating a new fork would be. Measurements show about a 2x
speedup during normal fuzzing operations. Performance may vary depending how
much memory got allocated for the forked VM. If it has been completely
deduplicated from the parent VM then creating a new fork would likely be more
performant.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@intel.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
---
v12: remove continuation & add comment back
address style issues pointed out by Jan
---
xen/arch/x86/mm/mem_sharing.c | 77 +++++++++++++++++++++++++++++++++++
xen/include/public/memory.h | 1 +
2 files changed, 78 insertions(+)
diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c
index faa79011c3..cc09f9c84f 100644
--- a/xen/arch/x86/mm/mem_sharing.c
+++ b/xen/arch/x86/mm/mem_sharing.c
@@ -1758,6 +1758,61 @@ static int fork(struct domain *cd, struct domain *d)
return rc;
}
+/*
+ * The fork reset operation is intended to be used on short-lived forks only.
+ * There is no hypercall continuation operation implemented for this reason.
+ * For forks that obtain a larger memory footprint it is likely going to be
+ * more performant to create a new fork instead of resetting an existing one.
+ *
+ * TODO: In case this hypercall would become useful on forks with larger memory
+ * footprints the hypercall continuation should be implemented (or if this
+ * feature needs to be become "stable").
+ */
+static int mem_sharing_fork_reset(struct domain *d, struct domain *pd)
+{
+ int rc;
+ struct p2m_domain *p2m = p2m_get_hostp2m(d);
+ struct page_info *page, *tmp;
+
+ domain_pause(d);
+
+ /* need recursive lock because we will free pages */
+ spin_lock_recursive(&d->page_alloc_lock);
+ page_list_for_each_safe(page, tmp, &d->page_list)
+ {
+ p2m_type_t p2mt;
+ p2m_access_t p2ma;
+ mfn_t mfn = page_to_mfn(page);
+ gfn_t gfn = mfn_to_gfn(d, mfn);
+
+ mfn = __get_gfn_type_access(p2m, gfn_x(gfn), &p2mt, &p2ma,
+ 0, NULL, false);
+
+ /* only reset pages that are sharable */
+ if ( !p2m_is_sharable(p2mt) )
+ continue;
+
+ /* take an extra reference or just skip if can't for whatever reason */
+ if ( !get_page(page, d) )
+ continue;
+
+ /* forked memory is 4k, not splitting large pages so this must work */
+ rc = p2m->set_entry(p2m, gfn, INVALID_MFN, PAGE_ORDER_4K,
+ p2m_invalid, p2m_access_rwx, -1);
+ ASSERT(!rc);
+
+ put_page_alloc_ref(page);
+ put_page(page);
+ }
+ spin_unlock_recursive(&d->page_alloc_lock);
+
+ rc = copy_settings(d, pd);
+
+ domain_unpause(d);
+
+ return rc;
+}
+
int mem_sharing_memop(XEN_GUEST_HANDLE_PARAM(xen_mem_sharing_op_t) arg)
{
int rc;
@@ -2048,6 +2103,28 @@ int mem_sharing_memop(XEN_GUEST_HANDLE_PARAM(xen_mem_sharing_op_t) arg)
break;
}
+ case XENMEM_sharing_op_fork_reset:
+ {
+ struct domain *pd;
+
+ rc = -EINVAL;
+ if ( mso.u.fork.pad[0] || mso.u.fork.pad[1] || mso.u.fork.pad[2] )
+ goto out;
+
+ rc = -ENOSYS;
+ if ( !d->parent )
+ goto out;
+
+ rc = rcu_lock_live_remote_domain_by_id(d->parent->domain_id, &pd);
+ if ( rc )
+ goto out;
+
+ rc = mem_sharing_fork_reset(d, pd);
+
+ rcu_unlock_domain(pd);
+ break;
+ }
+
default:
rc = -ENOSYS;
break;
diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
index 5ee4e0da12..d36d64b8dc 100644
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -483,6 +483,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_mem_access_op_t);
#define XENMEM_sharing_op_audit 7
#define XENMEM_sharing_op_range_share 8
#define XENMEM_sharing_op_fork 9
+#define XENMEM_sharing_op_fork_reset 10
#define XENMEM_SHARING_OP_S_HANDLE_INVALID (-10)
#define XENMEM_SHARING_OP_C_HANDLE_INVALID (-9)
--
2.20.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [Xen-devel] [PATCH v13 3/3] xen/tools: VM forking toolstack side
2020-03-30 15:02 [Xen-devel] [PATCH v13 0/3] VM forking Tamas K Lengyel
2020-03-30 15:02 ` [Xen-devel] [PATCH v13 1/3] xen/mem_sharing: " Tamas K Lengyel
2020-03-30 15:02 ` [Xen-devel] [PATCH v13 2/3] x86/mem_sharing: reset a fork Tamas K Lengyel
@ 2020-03-30 15:02 ` Tamas K Lengyel
2 siblings, 0 replies; 7+ messages in thread
From: Tamas K Lengyel @ 2020-03-30 15:02 UTC (permalink / raw)
To: xen-devel; +Cc: Anthony PERARD, Ian Jackson, Tamas K Lengyel, Wei Liu
Add necessary bits to implement "xl fork-vm" commands. The command allows the
user to specify how to launch the device model allowing for a late-launch model
in which the user can execute the fork without the device model and decide to
only later launch it.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@intel.com>
---
docs/man/xl.1.pod.in | 44 +++++
tools/libxc/include/xenctrl.h | 13 ++
tools/libxc/xc_memshr.c | 22 +++
tools/libxl/libxl.h | 11 ++
tools/libxl/libxl_create.c | 361 +++++++++++++++++++---------------
tools/libxl/libxl_dm.c | 2 +-
tools/libxl/libxl_dom.c | 43 +++-
tools/libxl/libxl_internal.h | 7 +
tools/libxl/libxl_types.idl | 1 +
tools/libxl/libxl_x86.c | 41 ++++
tools/xl/Makefile | 2 +-
tools/xl/xl.h | 5 +
tools/xl/xl_cmdtable.c | 15 ++
tools/xl/xl_forkvm.c | 147 ++++++++++++++
tools/xl/xl_vmcontrol.c | 14 ++
15 files changed, 562 insertions(+), 166 deletions(-)
create mode 100644 tools/xl/xl_forkvm.c
diff --git a/docs/man/xl.1.pod.in b/docs/man/xl.1.pod.in
index 09339282e6..59c03c6427 100644
--- a/docs/man/xl.1.pod.in
+++ b/docs/man/xl.1.pod.in
@@ -708,6 +708,50 @@ above).
=back
+=item B<fork-vm> [I<OPTIONS>] I<domain-id>
+
+Create a fork of a running VM. The domain will be paused after the operation
+and remains paused while forks of it exist. Experimental and x86 only.
+Forks can only be made of domains with HAP enabled and on Intel hardware. The
+parent domain must be created with the xl toolstack and its configuration must
+not manually define max_grant_frames, max_maptrack_frames or max_event_channels.
+
+B<OPTIONS>
+
+=over 4
+
+=item B<-p>
+
+Leave the fork paused after creating it.
+
+=item B<--launch-dm>
+
+Specify whether the device model (QEMU) should be launched for the fork. Late
+launch allows to start the device model for an already running fork.
+
+=item B<-C>
+
+The config file to use when launching the device model. Currently required when
+launching the device model. Most config settings MUST match the parent domain
+exactly, only change VM name, disk path and network configurations.
+
+=item B<-Q>
+
+The path to the qemu save file to use when launching the device model. Currently
+required when launching the device model.
+
+=item B<--fork-reset>
+
+Perform a reset operation of an already running fork. Note that resetting may
+be less performant then creating a new fork depending on how much memory the
+fork has deduplicated during its runtime.
+
+=item B<--max-vcpus>
+
+Specify the max-vcpus matching the parent domain when not launching the dm.
+
+=back
+
=item B<sharing> [I<domain-id>]
Display the number of shared pages for a specified domain. If no domain is
diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index fc6e57a1a0..00cb4cf1f7 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -2225,6 +2225,19 @@ int xc_memshr_range_share(xc_interface *xch,
uint64_t first_gfn,
uint64_t last_gfn);
+int xc_memshr_fork(xc_interface *xch,
+ uint32_t source_domain,
+ uint32_t client_domain);
+
+/*
+ * Note: this function is only intended to be used on short-lived forks that
+ * haven't yet aquired a lot of memory. In case the fork has a lot of memory
+ * it is likely more performant to create a new fork with xc_memshr_fork.
+ *
+ * With VMs that have a lot of memory this call may block for a long time.
+ */
+int xc_memshr_fork_reset(xc_interface *xch, uint32_t forked_domain);
+
/* Debug calls: return the number of pages referencing the shared frame backing
* the input argument. Should be one or greater.
*
diff --git a/tools/libxc/xc_memshr.c b/tools/libxc/xc_memshr.c
index 97e2e6a8d9..d0e4ee225b 100644
--- a/tools/libxc/xc_memshr.c
+++ b/tools/libxc/xc_memshr.c
@@ -239,6 +239,28 @@ int xc_memshr_debug_gref(xc_interface *xch,
return xc_memshr_memop(xch, domid, &mso);
}
+int xc_memshr_fork(xc_interface *xch, uint32_t pdomid, uint32_t domid)
+{
+ xen_mem_sharing_op_t mso;
+
+ memset(&mso, 0, sizeof(mso));
+
+ mso.op = XENMEM_sharing_op_fork;
+ mso.u.fork.parent_domain = pdomid;
+
+ return xc_memshr_memop(xch, domid, &mso);
+}
+
+int xc_memshr_fork_reset(xc_interface *xch, uint32_t domid)
+{
+ xen_mem_sharing_op_t mso;
+
+ memset(&mso, 0, sizeof(mso));
+ mso.op = XENMEM_sharing_op_fork_reset;
+
+ return xc_memshr_memop(xch, domid, &mso);
+}
+
int xc_memshr_audit(xc_interface *xch)
{
xen_mem_sharing_op_t mso;
diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
index 71709dc585..088e81c78b 100644
--- a/tools/libxl/libxl.h
+++ b/tools/libxl/libxl.h
@@ -2666,6 +2666,17 @@ int libxl_psr_get_hw_info(libxl_ctx *ctx, libxl_psr_feat_type type,
unsigned int lvl, unsigned int *nr,
libxl_psr_hw_info **info);
void libxl_psr_hw_info_list_free(libxl_psr_hw_info *list, unsigned int nr);
+
+int libxl_domain_fork_vm(libxl_ctx *ctx, uint32_t pdomid, uint32_t max_vcpus, uint32_t *domid)
+ LIBXL_EXTERNAL_CALLERS_ONLY;
+
+int libxl_domain_fork_launch_dm(libxl_ctx *ctx, libxl_domain_config *d_config,
+ uint32_t domid,
+ const libxl_asyncprogress_how *aop_console_how)
+ LIBXL_EXTERNAL_CALLERS_ONLY;
+
+int libxl_domain_fork_reset(libxl_ctx *ctx, uint32_t domid)
+ LIBXL_EXTERNAL_CALLERS_ONLY;
#endif
/* misc */
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index e7cb2dbc2b..5705b6e3a5 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -538,12 +538,12 @@ out:
return ret;
}
-int libxl__domain_make(libxl__gc *gc, libxl_domain_config *d_config,
- libxl__domain_build_state *state,
- uint32_t *domid, bool soft_reset)
+static int libxl__domain_make_xs_entries(libxl__gc *gc, libxl_domain_config *d_config,
+ libxl__domain_build_state *state,
+ uint32_t domid)
{
libxl_ctx *ctx = libxl__gc_owner(gc);
- int ret, rc, nb_vm;
+ int rc, nb_vm;
const char *dom_type;
char *uuid_string;
char *dom_path, *vm_path, *libxl_path;
@@ -555,9 +555,6 @@ int libxl__domain_make(libxl__gc *gc, libxl_domain_config *d_config,
/* convenience aliases */
libxl_domain_create_info *info = &d_config->c_info;
- libxl_domain_build_info *b_info = &d_config->b_info;
-
- assert(soft_reset || *domid == INVALID_DOMID);
uuid_string = libxl__uuid2string(gc, info->uuid);
if (!uuid_string) {
@@ -565,137 +562,7 @@ int libxl__domain_make(libxl__gc *gc, libxl_domain_config *d_config,
goto out;
}
- if (!soft_reset) {
- struct xen_domctl_createdomain create = {
- .ssidref = info->ssidref,
- .max_vcpus = b_info->max_vcpus,
- .max_evtchn_port = b_info->event_channels,
- .max_grant_frames = b_info->max_grant_frames,
- .max_maptrack_frames = b_info->max_maptrack_frames,
- };
-
- if (info->type != LIBXL_DOMAIN_TYPE_PV) {
- create.flags |= XEN_DOMCTL_CDF_hvm;
- create.flags |=
- libxl_defbool_val(info->hap) ? XEN_DOMCTL_CDF_hap : 0;
- create.flags |=
- libxl_defbool_val(info->oos) ? 0 : XEN_DOMCTL_CDF_oos_off;
- }
-
- assert(info->passthrough != LIBXL_PASSTHROUGH_DEFAULT);
- LOG(DETAIL, "passthrough: %s",
- libxl_passthrough_to_string(info->passthrough));
-
- if (info->passthrough != LIBXL_PASSTHROUGH_DISABLED)
- create.flags |= XEN_DOMCTL_CDF_iommu;
-
- if (info->passthrough == LIBXL_PASSTHROUGH_SYNC_PT)
- create.iommu_opts |= XEN_DOMCTL_IOMMU_no_sharept;
-
- /* Ultimately, handle is an array of 16 uint8_t, same as uuid */
- libxl_uuid_copy(ctx, (libxl_uuid *)&create.handle, &info->uuid);
-
- ret = libxl__arch_domain_prepare_config(gc, d_config, &create);
- if (ret < 0) {
- LOGED(ERROR, *domid, "fail to get domain config");
- rc = ERROR_FAIL;
- goto out;
- }
-
- for (;;) {
- uint32_t local_domid;
- bool recent;
-
- if (info->domid == RANDOM_DOMID) {
- uint16_t v;
-
- ret = libxl__random_bytes(gc, (void *)&v, sizeof(v));
- if (ret < 0)
- break;
-
- v &= DOMID_MASK;
- if (!libxl_domid_valid_guest(v))
- continue;
-
- local_domid = v;
- } else {
- local_domid = info->domid; /* May not be valid */
- }
-
- ret = xc_domain_create(ctx->xch, &local_domid, &create);
- if (ret < 0) {
- /*
- * If we generated a random domid and creation failed
- * because that domid already exists then simply try
- * again.
- */
- if (errno == EEXIST && info->domid == RANDOM_DOMID)
- continue;
-
- LOGED(ERROR, local_domid, "domain creation fail");
- rc = ERROR_FAIL;
- goto out;
- }
-
- /* A new domain now exists */
- *domid = local_domid;
-
- rc = libxl__is_domid_recent(gc, local_domid, &recent);
- if (rc)
- goto out;
-
- /* The domid is not recent, so we're done */
- if (!recent)
- break;
-
- /*
- * If the domid was specified then there's no point in
- * trying again.
- */
- if (libxl_domid_valid_guest(info->domid)) {
- LOGED(ERROR, local_domid, "domain id recently used");
- rc = ERROR_FAIL;
- goto out;
- }
-
- /*
- * The domain is recent and so cannot be used. Clear domid
- * here since, if xc_domain_destroy() fails below there is
- * little point calling it again in the error path.
- */
- *domid = INVALID_DOMID;
-
- ret = xc_domain_destroy(ctx->xch, local_domid);
- if (ret < 0) {
- LOGED(ERROR, local_domid, "domain destroy fail");
- rc = ERROR_FAIL;
- goto out;
- }
-
- /* The domain was successfully destroyed, so we can try again */
- }
-
- rc = libxl__arch_domain_save_config(gc, d_config, state, &create);
- if (rc < 0)
- goto out;
- }
-
- /*
- * If soft_reset is set the the domid will have been valid on entry.
- * If it was not set then xc_domain_create() should have assigned a
- * valid value. Either way, if we reach this point, domid should be
- * valid.
- */
- assert(libxl_domid_valid_guest(*domid));
-
- ret = xc_cpupool_movedomain(ctx->xch, info->poolid, *domid);
- if (ret < 0) {
- LOGED(ERROR, *domid, "domain move fail");
- rc = ERROR_FAIL;
- goto out;
- }
-
- dom_path = libxl__xs_get_dompath(gc, *domid);
+ dom_path = libxl__xs_get_dompath(gc, domid);
if (!dom_path) {
rc = ERROR_FAIL;
goto out;
@@ -703,12 +570,12 @@ int libxl__domain_make(libxl__gc *gc, libxl_domain_config *d_config,
vm_path = GCSPRINTF("/vm/%s", uuid_string);
if (!vm_path) {
- LOGD(ERROR, *domid, "cannot allocate create paths");
+ LOGD(ERROR, domid, "cannot allocate create paths");
rc = ERROR_FAIL;
goto out;
}
- libxl_path = libxl__xs_libxl_path(gc, *domid);
+ libxl_path = libxl__xs_libxl_path(gc, domid);
if (!libxl_path) {
rc = ERROR_FAIL;
goto out;
@@ -719,10 +586,10 @@ int libxl__domain_make(libxl__gc *gc, libxl_domain_config *d_config,
roperm[0].id = 0;
roperm[0].perms = XS_PERM_NONE;
- roperm[1].id = *domid;
+ roperm[1].id = domid;
roperm[1].perms = XS_PERM_READ;
- rwperm[0].id = *domid;
+ rwperm[0].id = domid;
rwperm[0].perms = XS_PERM_NONE;
retry_transaction:
@@ -740,7 +607,7 @@ retry_transaction:
noperm, ARRAY_SIZE(noperm));
xs_write(ctx->xsh, t, GCSPRINTF("%s/vm", dom_path), vm_path, strlen(vm_path));
- rc = libxl__domain_rename(gc, *domid, 0, info->name, t);
+ rc = libxl__domain_rename(gc, domid, 0, info->name, t);
if (rc)
goto out;
@@ -830,7 +697,7 @@ retry_transaction:
vm_list = libxl_list_vm(ctx, &nb_vm);
if (!vm_list) {
- LOGD(ERROR, *domid, "cannot get number of running guests");
+ LOGD(ERROR, domid, "cannot get number of running guests");
rc = ERROR_FAIL;
goto out;
}
@@ -854,7 +721,7 @@ retry_transaction:
t = 0;
goto retry_transaction;
}
- LOGED(ERROR, *domid, "domain creation ""xenstore transaction commit failed");
+ LOGED(ERROR, domid, "domain creation ""xenstore transaction commit failed");
rc = ERROR_FAIL;
goto out;
}
@@ -866,6 +733,155 @@ retry_transaction:
return rc;
}
+int libxl__domain_make(libxl__gc *gc, libxl_domain_config *d_config,
+ libxl__domain_build_state *state,
+ uint32_t *domid, bool soft_reset)
+{
+ libxl_ctx *ctx = libxl__gc_owner(gc);
+ int ret, rc;
+
+ /* convenience aliases */
+ libxl_domain_create_info *info = &d_config->c_info;
+ libxl_domain_build_info *b_info = &d_config->b_info;
+
+ assert(soft_reset || *domid == INVALID_DOMID);
+
+ if (!soft_reset) {
+ struct xen_domctl_createdomain create = {
+ .ssidref = info->ssidref,
+ .max_vcpus = b_info->max_vcpus,
+ .max_evtchn_port = b_info->event_channels,
+ .max_grant_frames = b_info->max_grant_frames,
+ .max_maptrack_frames = b_info->max_maptrack_frames,
+ };
+
+ if (info->type != LIBXL_DOMAIN_TYPE_PV) {
+ create.flags |= XEN_DOMCTL_CDF_hvm;
+ create.flags |=
+ libxl_defbool_val(info->hap) ? XEN_DOMCTL_CDF_hap : 0;
+ create.flags |=
+ libxl_defbool_val(info->oos) ? 0 : XEN_DOMCTL_CDF_oos_off;
+ }
+
+ assert(info->passthrough != LIBXL_PASSTHROUGH_DEFAULT);
+ LOG(DETAIL, "passthrough: %s",
+ libxl_passthrough_to_string(info->passthrough));
+
+ if (info->passthrough != LIBXL_PASSTHROUGH_DISABLED)
+ create.flags |= XEN_DOMCTL_CDF_iommu;
+
+ if (info->passthrough == LIBXL_PASSTHROUGH_SYNC_PT)
+ create.iommu_opts |= XEN_DOMCTL_IOMMU_no_sharept;
+
+ /* Ultimately, handle is an array of 16 uint8_t, same as uuid */
+ libxl_uuid_copy(ctx, (libxl_uuid *)&create.handle, &info->uuid);
+
+ ret = libxl__arch_domain_prepare_config(gc, d_config, &create);
+ if (ret < 0) {
+ LOGED(ERROR, *domid, "fail to get domain config");
+ rc = ERROR_FAIL;
+ goto out;
+ }
+
+ for (;;) {
+ uint32_t local_domid;
+ bool recent;
+
+ if (info->domid == RANDOM_DOMID) {
+ uint16_t v;
+
+ ret = libxl__random_bytes(gc, (void *)&v, sizeof(v));
+ if (ret < 0)
+ break;
+
+ v &= DOMID_MASK;
+ if (!libxl_domid_valid_guest(v))
+ continue;
+
+ local_domid = v;
+ } else {
+ local_domid = info->domid; /* May not be valid */
+ }
+
+ ret = xc_domain_create(ctx->xch, &local_domid, &create);
+ if (ret < 0) {
+ /*
+ * If we generated a random domid and creation failed
+ * because that domid already exists then simply try
+ * again.
+ */
+ if (errno == EEXIST && info->domid == RANDOM_DOMID)
+ continue;
+
+ LOGED(ERROR, local_domid, "domain creation fail");
+ rc = ERROR_FAIL;
+ goto out;
+ }
+
+ /* A new domain now exists */
+ *domid = local_domid;
+
+ rc = libxl__is_domid_recent(gc, local_domid, &recent);
+ if (rc)
+ goto out;
+
+ /* The domid is not recent, so we're done */
+ if (!recent)
+ break;
+
+ /*
+ * If the domid was specified then there's no point in
+ * trying again.
+ */
+ if (libxl_domid_valid_guest(info->domid)) {
+ LOGED(ERROR, local_domid, "domain id recently used");
+ rc = ERROR_FAIL;
+ goto out;
+ }
+
+ /*
+ * The domain is recent and so cannot be used. Clear domid
+ * here since, if xc_domain_destroy() fails below there is
+ * little point calling it again in the error path.
+ */
+ *domid = INVALID_DOMID;
+
+ ret = xc_domain_destroy(ctx->xch, local_domid);
+ if (ret < 0) {
+ LOGED(ERROR, local_domid, "domain destroy fail");
+ rc = ERROR_FAIL;
+ goto out;
+ }
+
+ /* The domain was successfully destroyed, so we can try again */
+ }
+
+ rc = libxl__arch_domain_save_config(gc, d_config, state, &create);
+ if (rc < 0)
+ goto out;
+ }
+
+ /*
+ * If soft_reset is set the the domid will have been valid on entry.
+ * If it was not set then xc_domain_create() should have assigned a
+ * valid value. Either way, if we reach this point, domid should be
+ * valid.
+ */
+ assert(libxl_domid_valid_guest(*domid));
+
+ ret = xc_cpupool_movedomain(ctx->xch, info->poolid, *domid);
+ if (ret < 0) {
+ LOGED(ERROR, *domid, "domain move fail");
+ rc = ERROR_FAIL;
+ goto out;
+ }
+
+ rc = libxl__domain_make_xs_entries(gc, d_config, state, *domid);
+
+out:
+ return rc;
+}
+
static int store_libxl_entry(libxl__gc *gc, uint32_t domid,
libxl_domain_build_info *b_info)
{
@@ -1191,16 +1207,32 @@ static void initiate_domain_create(libxl__egc *egc,
ret = libxl__domain_config_setdefault(gc,d_config,domid);
if (ret) goto error_out;
- ret = libxl__domain_make(gc, d_config, &dcs->build_state, &domid,
- dcs->soft_reset);
- if (ret) {
- LOGD(ERROR, domid, "cannot make domain: %d", ret);
+ if ( !d_config->dm_restore_file )
+ {
+ ret = libxl__domain_make(gc, d_config, &dcs->build_state, &domid,
+ dcs->soft_reset);
dcs->guest_domid = domid;
+
+ if (ret) {
+ LOGD(ERROR, domid, "cannot make domain: %d", ret);
+ ret = ERROR_FAIL;
+ goto error_out;
+ }
+ } else if ( dcs->guest_domid != INVALID_DOMID ) {
+ domid = dcs->guest_domid;
+
+ ret = libxl__domain_make_xs_entries(gc, d_config, &dcs->build_state, domid);
+ if (ret) {
+ LOGD(ERROR, domid, "cannot make domain: %d", ret);
+ ret = ERROR_FAIL;
+ goto error_out;
+ }
+ } else {
+ LOGD(ERROR, domid, "cannot make domain");
ret = ERROR_FAIL;
goto error_out;
}
- dcs->guest_domid = domid;
dcs->sdss.dm.guest_domid = 0; /* means we haven't spawned */
/* post-4.13 todo: move these next bits of defaulting to
@@ -1236,7 +1268,7 @@ static void initiate_domain_create(libxl__egc *egc,
if (ret)
goto error_out;
- if (restore_fd >= 0 || dcs->soft_reset) {
+ if (restore_fd >= 0 || dcs->soft_reset || d_config->dm_restore_file) {
LOGD(DEBUG, domid, "restoring, not running bootloader");
domcreate_bootloader_done(egc, &dcs->bl, 0);
} else {
@@ -1312,7 +1344,16 @@ static void domcreate_bootloader_done(libxl__egc *egc,
dcs->sdss.dm.callback = domcreate_devmodel_started;
dcs->sdss.callback = domcreate_devmodel_started;
- if (restore_fd < 0 && !dcs->soft_reset) {
+ if (restore_fd < 0 && !dcs->soft_reset && !d_config->dm_restore_file) {
+ rc = libxl__domain_build(gc, d_config, domid, state);
+ domcreate_rebuild_done(egc, dcs, rc);
+ return;
+ }
+
+ if ( d_config->dm_restore_file ) {
+ dcs->srs.dcs = dcs;
+ dcs->srs.ao = ao;
+ state->forked_vm = true;
rc = libxl__domain_build(gc, d_config, domid, state);
domcreate_rebuild_done(egc, dcs, rc);
return;
@@ -1510,6 +1551,7 @@ static void domcreate_rebuild_done(libxl__egc *egc,
/* convenience aliases */
const uint32_t domid = dcs->guest_domid;
libxl_domain_config *const d_config = dcs->guest_config;
+ libxl__domain_build_state *const state = &dcs->build_state;
if (ret) {
LOGD(ERROR, domid, "cannot (re-)build domain: %d", ret);
@@ -1517,6 +1559,9 @@ static void domcreate_rebuild_done(libxl__egc *egc,
goto error_out;
}
+ if ( d_config->dm_restore_file )
+ state->saved_state = GCSPRINTF("%s", d_config->dm_restore_file);
+
store_libxl_entry(gc, domid, &d_config->b_info);
libxl__multidev_begin(ao, &dcs->multidev);
@@ -1947,7 +1992,7 @@ static void domain_create_cb(libxl__egc *egc,
libxl__domain_create_state *dcs,
int rc, uint32_t domid);
-static int do_domain_create(libxl_ctx *ctx, libxl_domain_config *d_config,
+int libxl__do_domain_create(libxl_ctx *ctx, libxl_domain_config *d_config,
uint32_t *domid, int restore_fd, int send_back_fd,
const libxl_domain_restore_params *params,
const libxl_asyncop_how *ao_how,
@@ -1960,6 +2005,8 @@ static int do_domain_create(libxl_ctx *ctx, libxl_domain_config *d_config,
GCNEW(cdcs);
cdcs->dcs.ao = ao;
cdcs->dcs.guest_config = d_config;
+ cdcs->dcs.guest_domid = *domid;
+
libxl_domain_config_init(&cdcs->dcs.guest_config_saved);
libxl_domain_config_copy(ctx, &cdcs->dcs.guest_config_saved, d_config);
cdcs->dcs.restore_fd = cdcs->dcs.libxc_fd = restore_fd;
@@ -2204,8 +2251,8 @@ int libxl_domain_create_new(libxl_ctx *ctx, libxl_domain_config *d_config,
const libxl_asyncprogress_how *aop_console_how)
{
unset_disk_colo_restore(d_config);
- return do_domain_create(ctx, d_config, domid, -1, -1, NULL,
- ao_how, aop_console_how);
+ return libxl__do_domain_create(ctx, d_config, domid, -1, -1, NULL,
+ ao_how, aop_console_how);
}
int libxl_domain_create_restore(libxl_ctx *ctx, libxl_domain_config *d_config,
@@ -2221,8 +2268,8 @@ int libxl_domain_create_restore(libxl_ctx *ctx, libxl_domain_config *d_config,
unset_disk_colo_restore(d_config);
}
- return do_domain_create(ctx, d_config, domid, restore_fd, send_back_fd,
- params, ao_how, aop_console_how);
+ return libxl__do_domain_create(ctx, d_config, domid, restore_fd, send_back_fd,
+ params, ao_how, aop_console_how);
}
int libxl_domain_soft_reset(libxl_ctx *ctx,
diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index f4007bbe50..b615f1fc88 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -2803,7 +2803,7 @@ static void device_model_spawn_outcome(libxl__egc *egc,
libxl__domain_build_state *state = dmss->build_state;
- if (state->saved_state) {
+ if (state->saved_state && !state->forked_vm) {
ret2 = unlink(state->saved_state);
if (ret2) {
LOGED(ERROR, dmss->guest_domid, "%s: failed to remove device-model state %s",
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 71cb578923..3bc7117b99 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -249,9 +249,12 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid,
libxl_domain_build_info *const info = &d_config->b_info;
libxl_ctx *ctx = libxl__gc_owner(gc);
char *xs_domid, *con_domid;
- int rc;
+ int rc = 0;
uint64_t size;
+ if ( state->forked_vm )
+ goto skip_fork;
+
if (xc_domain_max_vcpus(ctx->xch, domid, info->max_vcpus) != 0) {
LOG(ERROR, "Couldn't set max vcpu count");
return ERROR_FAIL;
@@ -362,7 +365,6 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid,
}
}
-
rc = libxl__arch_extra_memory(gc, info, &size);
if (rc < 0) {
LOGE(ERROR, "Couldn't get arch extra constant memory size");
@@ -374,6 +376,11 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid,
return ERROR_FAIL;
}
+ rc = libxl__arch_domain_create(gc, d_config, domid);
+ if ( rc )
+ goto out;
+
+skip_fork:
xs_domid = xs_read(ctx->xsh, XBT_NULL, "/tool/xenstored/domid", NULL);
state->store_domid = xs_domid ? atoi(xs_domid) : 0;
free(xs_domid);
@@ -385,8 +392,7 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid,
state->store_port = xc_evtchn_alloc_unbound(ctx->xch, domid, state->store_domid);
state->console_port = xc_evtchn_alloc_unbound(ctx->xch, domid, state->console_domid);
- rc = libxl__arch_domain_create(gc, d_config, domid);
-
+out:
return rc;
}
@@ -444,6 +450,9 @@ int libxl__build_post(libxl__gc *gc, uint32_t domid,
char **ents;
int i, rc;
+ if ( state->forked_vm )
+ goto skip_fork;
+
if (info->num_vnuma_nodes && !info->num_vcpu_soft_affinity) {
rc = set_vnuma_affinity(gc, domid, info);
if (rc)
@@ -466,6 +475,7 @@ int libxl__build_post(libxl__gc *gc, uint32_t domid,
}
}
+skip_fork:
ents = libxl__calloc(gc, 12 + (info->max_vcpus * 2) + 2, sizeof(char *));
ents[0] = "memory/static-max";
ents[1] = GCSPRINTF("%"PRId64, info->max_memkb);
@@ -728,14 +738,16 @@ static int hvm_build_set_params(xc_interface *handle, uint32_t domid,
libxl_domain_build_info *info,
int store_evtchn, unsigned long *store_mfn,
int console_evtchn, unsigned long *console_mfn,
- domid_t store_domid, domid_t console_domid)
+ domid_t store_domid, domid_t console_domid,
+ bool forked_vm)
{
struct hvm_info_table *va_hvm;
uint8_t *va_map, sum;
uint64_t str_mfn, cons_mfn;
int i;
- if (info->type == LIBXL_DOMAIN_TYPE_HVM) {
+ if ( info->type == LIBXL_DOMAIN_TYPE_HVM && !forked_vm )
+ {
va_map = xc_map_foreign_range(handle, domid,
XC_PAGE_SIZE, PROT_READ | PROT_WRITE,
HVM_INFO_PFN);
@@ -1051,6 +1063,23 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
struct xc_dom_image *dom = NULL;
bool device_model = info->type == LIBXL_DOMAIN_TYPE_HVM ? true : false;
+ if ( state->forked_vm )
+ {
+ rc = hvm_build_set_params(ctx->xch, domid, info, state->store_port,
+ &state->store_mfn, state->console_port,
+ &state->console_mfn, state->store_domid,
+ state->console_domid, state->forked_vm);
+
+ if ( rc )
+ return rc;
+
+ return xc_dom_gnttab_seed(ctx->xch, domid, true,
+ state->console_mfn,
+ state->store_mfn,
+ state->console_domid,
+ state->store_domid);
+ }
+
xc_dom_loginit(ctx->xch);
/*
@@ -1175,7 +1204,7 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
rc = hvm_build_set_params(ctx->xch, domid, info, state->store_port,
&state->store_mfn, state->console_port,
&state->console_mfn, state->store_domid,
- state->console_domid);
+ state->console_domid, false);
if (rc != 0) {
LOG(ERROR, "hvm build set params failed");
goto out;
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 5f39e44cb9..d05ff31e83 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -1374,6 +1374,7 @@ typedef struct {
char *saved_state;
int dm_monitor_fd;
+ bool forked_vm;
libxl__file_reference pv_kernel;
libxl__file_reference pv_ramdisk;
@@ -4818,6 +4819,12 @@ _hidden int libxl__domain_pvcontrol(libxl__egc *egc,
/* Check whether a domid is recent */
int libxl__is_domid_recent(libxl__gc *gc, uint32_t domid, bool *recent);
+_hidden int libxl__do_domain_create(libxl_ctx *ctx, libxl_domain_config *d_config,
+ uint32_t *domid, int restore_fd, int send_back_fd,
+ const libxl_domain_restore_params *params,
+ const libxl_asyncop_how *ao_how,
+ const libxl_asyncprogress_how *aop_console_how);
+
#endif
/*
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index f7c473be74..2bb5e6319e 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -958,6 +958,7 @@ libxl_domain_config = Struct("domain_config", [
("on_watchdog", libxl_action_on_shutdown),
("on_crash", libxl_action_on_shutdown),
("on_soft_reset", libxl_action_on_shutdown),
+ ("dm_restore_file", string, {'const': True}),
], dir=DIR_IN)
libxl_diskinfo = Struct("diskinfo", [
diff --git a/tools/libxl/libxl_x86.c b/tools/libxl/libxl_x86.c
index f8bc828e62..f4312411fc 100644
--- a/tools/libxl/libxl_x86.c
+++ b/tools/libxl/libxl_x86.c
@@ -2,6 +2,7 @@
#include "libxl_arch.h"
#include <xc_dom.h>
+#include <xen-xsm/flask/flask.h>
int libxl__arch_domain_prepare_config(libxl__gc *gc,
libxl_domain_config *d_config,
@@ -842,6 +843,46 @@ int libxl__arch_passthrough_mode_setdefault(libxl__gc *gc,
return rc;
}
+/*
+ * The parent domain is expected to be created with default settings for
+ * - max_evtch_port
+ * - max_grant_frames
+ * - max_maptrack_frames
+ */
+int libxl_domain_fork_vm(libxl_ctx *ctx, uint32_t pdomid, uint32_t max_vcpus, uint32_t *domid)
+{
+ int rc;
+ struct xen_domctl_createdomain create = {0};
+ create.flags |= XEN_DOMCTL_CDF_hvm;
+ create.flags |= XEN_DOMCTL_CDF_hap;
+ create.flags |= XEN_DOMCTL_CDF_oos_off;
+ create.arch.emulation_flags = (XEN_X86_EMU_ALL & ~XEN_X86_EMU_VPCI);
+ create.ssidref = SECINITSID_DOMU;
+ create.max_vcpus = max_vcpus;
+ create.max_evtchn_port = 1023;
+ create.max_grant_frames = LIBXL_MAX_GRANT_FRAMES_DEFAULT;
+ create.max_maptrack_frames = LIBXL_MAX_MAPTRACK_FRAMES_DEFAULT;
+
+ if ( (rc = xc_domain_create(ctx->xch, domid, &create)) )
+ return rc;
+
+ if ( (rc = xc_memshr_fork(ctx->xch, pdomid, *domid)) )
+ xc_domain_destroy(ctx->xch, *domid);
+
+ return rc;
+}
+
+int libxl_domain_fork_launch_dm(libxl_ctx *ctx, libxl_domain_config *d_config,
+ uint32_t domid,
+ const libxl_asyncprogress_how *aop_console_how)
+{
+ return libxl__do_domain_create(ctx, d_config, &domid, -1, -1, 0, 0, aop_console_how);
+}
+
+int libxl_domain_fork_reset(libxl_ctx *ctx, uint32_t domid)
+{
+ return xc_memshr_fork_reset(ctx->xch, domid);
+}
/*
* Local variables:
diff --git a/tools/xl/Makefile b/tools/xl/Makefile
index af4912e67a..073222233b 100644
--- a/tools/xl/Makefile
+++ b/tools/xl/Makefile
@@ -15,7 +15,7 @@ LDFLAGS += $(PTHREAD_LDFLAGS)
CFLAGS_XL += $(CFLAGS_libxenlight)
CFLAGS_XL += -Wshadow
-XL_OBJS-$(CONFIG_X86) = xl_psr.o
+XL_OBJS-$(CONFIG_X86) = xl_psr.o xl_forkvm.o
XL_OBJS = xl.o xl_cmdtable.o xl_sxp.o xl_utils.o $(XL_OBJS-y)
XL_OBJS += xl_parse.o xl_cpupool.o xl_flask.o
XL_OBJS += xl_vtpm.o xl_block.o xl_nic.o xl_usb.o
diff --git a/tools/xl/xl.h b/tools/xl/xl.h
index 06569c6c4a..1105c34b15 100644
--- a/tools/xl/xl.h
+++ b/tools/xl/xl.h
@@ -31,6 +31,7 @@ struct cmd_spec {
};
struct domain_create {
+ uint32_t ddomid; /* fork launch dm for this domid */
int debug;
int daemonize;
int monitor; /* handle guest reboots etc */
@@ -45,6 +46,7 @@ struct domain_create {
const char *config_file;
char *extra_config; /* extra config string */
const char *restore_file;
+ const char *dm_restore_file;
char *colo_proxy_script;
bool userspace_colo_proxy;
int migrate_fd; /* -1 means none */
@@ -128,6 +130,8 @@ int main_pciassignable_remove(int argc, char **argv);
int main_pciassignable_list(int argc, char **argv);
#ifndef LIBXL_HAVE_NO_SUSPEND_RESUME
int main_restore(int argc, char **argv);
+int main_fork_launch_dm(int argc, char **argv);
+int main_fork_reset(int argc, char **argv);
int main_migrate_receive(int argc, char **argv);
int main_save(int argc, char **argv);
int main_migrate(int argc, char **argv);
@@ -212,6 +216,7 @@ int main_psr_cat_cbm_set(int argc, char **argv);
int main_psr_cat_show(int argc, char **argv);
int main_psr_mba_set(int argc, char **argv);
int main_psr_mba_show(int argc, char **argv);
+int main_fork_vm(int argc, char **argv);
#endif
int main_qemu_monitor_command(int argc, char **argv);
diff --git a/tools/xl/xl_cmdtable.c b/tools/xl/xl_cmdtable.c
index 08335394e5..ef634abf32 100644
--- a/tools/xl/xl_cmdtable.c
+++ b/tools/xl/xl_cmdtable.c
@@ -187,6 +187,21 @@ struct cmd_spec cmd_table[] = {
"Restore a domain from a saved state",
"- for internal use only",
},
+#if defined(__i386__) || defined(__x86_64__)
+ { "fork-vm",
+ &main_fork_vm, 0, 1,
+ "Fork a domain from the running parent domid. Experimental. Most config settings must match parent.",
+ "[options] <Domid>",
+ "-h Print this help.\n"
+ "-C <config> Use config file for VM fork.\n"
+ "-Q <qemu-save-file> Use qemu save file for VM fork.\n"
+ "--launch-dm <yes|no|late> Launch device model (QEMU) for VM fork.\n"
+ "--fork-reset Reset VM fork.\n"
+ "--max-vcpus Specify max-vcpus matching the parent domain when not launching dm\n"
+ "-p Do not unpause fork VM after operation.\n"
+ "-d Enable debug messages.\n"
+ },
+#endif
#endif
{ "dump-core",
&main_dump_core, 0, 1,
diff --git a/tools/xl/xl_forkvm.c b/tools/xl/xl_forkvm.c
new file mode 100644
index 0000000000..a7ee5b4771
--- /dev/null
+++ b/tools/xl/xl_forkvm.c
@@ -0,0 +1,147 @@
+/*
+ * Copyright 2020 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; version 2.1 only. with the special
+ * exception on linking described in file LICENSE.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ */
+
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/utsname.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <libxl.h>
+#include <libxl_utils.h>
+#include <libxlutil.h>
+
+#include "xl.h"
+#include "xl_utils.h"
+#include "xl_parse.h"
+
+int main_fork_vm(int argc, char **argv)
+{
+ int rc, debug = 0;
+ uint32_t domid_in = INVALID_DOMID, domid_out = INVALID_DOMID;
+ int launch_dm = 1;
+ bool reset = 0;
+ bool pause = 0;
+ const char *config_file = NULL;
+ const char *dm_restore_file = NULL;
+ uint32_t max_vcpus = 0;
+
+ int opt;
+ static struct option opts[] = {
+ {"launch-dm", 1, 0, 'l'},
+ {"fork-reset", 0, 0, 'r'},
+ {"max-vcpus", 1, 0, 'm'},
+ COMMON_LONG_OPTS
+ };
+
+ SWITCH_FOREACH_OPT(opt, "phdC:Q:l:rm:N:D:B:V:", opts, "fork-vm", 1) {
+ case 'd':
+ debug = 1;
+ break;
+ case 'p':
+ pause = 1;
+ break;
+ case 'm':
+ max_vcpus = atoi(optarg);
+ break;
+ case 'C':
+ config_file = optarg;
+ break;
+ case 'Q':
+ dm_restore_file = optarg;
+ break;
+ case 'l':
+ if ( !strcmp(optarg, "no") )
+ launch_dm = 0;
+ if ( !strcmp(optarg, "yes") )
+ launch_dm = 1;
+ if ( !strcmp(optarg, "late") )
+ launch_dm = 2;
+ break;
+ case 'r':
+ reset = 1;
+ break;
+ case 'N': /* fall-through */
+ case 'D': /* fall-through */
+ case 'B': /* fall-through */
+ case 'V':
+ fprintf(stderr, "Unimplemented option(s)\n");
+ return EXIT_FAILURE;
+ }
+
+ if (argc-optind == 1) {
+ domid_in = atoi(argv[optind]);
+ } else {
+ help("fork-vm");
+ return EXIT_FAILURE;
+ }
+
+ if (launch_dm && (!config_file || !dm_restore_file)) {
+ fprintf(stderr, "Currently you must provide both -C and -Q options\n");
+ return EXIT_FAILURE;
+ }
+
+ if (reset) {
+ domid_out = domid_in;
+ if (libxl_domain_fork_reset(ctx, domid_in) == EXIT_FAILURE)
+ return EXIT_FAILURE;
+ }
+
+ if (launch_dm == 2 || reset) {
+ domid_out = domid_in;
+ rc = EXIT_SUCCESS;
+ } else {
+ if ( !max_vcpus )
+ {
+ fprintf(stderr, "Currently you must parent's max_vcpu for this option\n");
+ return EXIT_FAILURE;
+ }
+
+ rc = libxl_domain_fork_vm(ctx, domid_in, max_vcpus, &domid_out);
+ }
+
+ if (rc == EXIT_SUCCESS) {
+ if ( launch_dm ) {
+ struct domain_create dom_info;
+ memset(&dom_info, 0, sizeof(dom_info));
+ dom_info.ddomid = domid_out;
+ dom_info.dm_restore_file = dm_restore_file;
+ dom_info.debug = debug;
+ dom_info.paused = pause;
+ dom_info.config_file = config_file;
+ dom_info.migrate_fd = -1;
+ dom_info.send_back_fd = -1;
+ rc = create_domain(&dom_info) < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+ } else if ( !pause )
+ rc = libxl_domain_unpause(ctx, domid_out, NULL);
+ }
+
+ if (rc == EXIT_SUCCESS)
+ fprintf(stderr, "fork-vm command successfully returned domid: %u\n", domid_out);
+ else if ( domid_out != INVALID_DOMID )
+ libxl_domain_destroy(ctx, domid_out, 0);
+
+ return rc;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/tools/xl/xl_vmcontrol.c b/tools/xl/xl_vmcontrol.c
index 2e2d427492..782fbbc24b 100644
--- a/tools/xl/xl_vmcontrol.c
+++ b/tools/xl/xl_vmcontrol.c
@@ -676,6 +676,12 @@ int create_domain(struct domain_create *dom_info)
int restoring = (restore_file || (migrate_fd >= 0));
+#if defined(__i386__) || defined(__x86_64__)
+ /* VM forking */
+ uint32_t ddomid = dom_info->ddomid; // launch dm for this domain iff set
+ const char *dm_restore_file = dom_info->dm_restore_file;
+#endif
+
libxl_domain_config_init(&d_config);
if (restoring) {
@@ -926,6 +932,14 @@ start:
* restore/migrate-receive it again.
*/
restoring = 0;
+#if defined(__i386__) || defined(__x86_64__)
+ } else if ( ddomid ) {
+ d_config.dm_restore_file = dm_restore_file;
+ ret = libxl_domain_fork_launch_dm(ctx, &d_config, ddomid,
+ autoconnect_console_how);
+ domid = ddomid;
+ ddomid = INVALID_DOMID;
+#endif
} else if (domid_soft_reset != INVALID_DOMID) {
/* Do soft reset. */
ret = libxl_domain_soft_reset(ctx, &d_config, domid_soft_reset,
--
2.20.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v13 1/3] xen/mem_sharing: VM forking
2020-03-30 15:02 ` [Xen-devel] [PATCH v13 1/3] xen/mem_sharing: " Tamas K Lengyel
@ 2020-03-31 10:09 ` Julien Grall
2020-04-06 10:52 ` Roger Pau Monné
1 sibling, 0 replies; 7+ messages in thread
From: Julien Grall @ 2020-03-31 10:09 UTC (permalink / raw)
To: Tamas K Lengyel, xen-devel
Cc: Stefano Stabellini, Wei Liu, Andrew Cooper, Ian Jackson,
George Dunlap, Tamas K Lengyel, Jan Beulich, Volodymyr Babchuk,
Roger Pau Monné
Hi,
On 30/03/2020 16:02, Tamas K Lengyel wrote:
> VM forking is the process of creating a domain with an empty memory space and a
> parent domain specified from which to populate the memory when necessary. For
> the new domain to be functional the VM state is copied over as part of the fork
> operation (HVM params, hap allocation, etc).
>
> Signed-off-by: Tamas K Lengyel <tamas.lengyel@intel.com>
> Acked-by: Jan Beulich <jbeulich@suse.com>
> ---
> v13: Address issues pointed out by Roger & Jan
> Introduce & use PAGE_OFFSET to calculate vcpu_info offset
> ---
> xen/arch/x86/domain.c | 13 ++
> xen/arch/x86/hvm/hvm.c | 4 +-
> xen/arch/x86/mm/hap/hap.c | 3 +-
> xen/arch/x86/mm/mem_sharing.c | 351 ++++++++++++++++++++++++++++++
> xen/arch/x86/mm/p2m.c | 9 +-
> xen/include/asm-arm/page.h | 1 +
For the Arm change:
Acked-by: Julien Grall <jgrall@amazon.com>
Cheers,
--
Julien Grall
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v13 1/3] xen/mem_sharing: VM forking
2020-03-30 15:02 ` [Xen-devel] [PATCH v13 1/3] xen/mem_sharing: " Tamas K Lengyel
2020-03-31 10:09 ` Julien Grall
@ 2020-04-06 10:52 ` Roger Pau Monné
2020-04-06 14:07 ` Tamas K Lengyel
1 sibling, 1 reply; 7+ messages in thread
From: Roger Pau Monné @ 2020-04-06 10:52 UTC (permalink / raw)
To: Tamas K Lengyel
Cc: Stefano Stabellini, Julien Grall, Wei Liu, Andrew Cooper,
Ian Jackson, George Dunlap, Tamas K Lengyel, Jan Beulich,
xen-devel, Volodymyr Babchuk
On Mon, Mar 30, 2020 at 08:02:08AM -0700, Tamas K Lengyel wrote:
> VM forking is the process of creating a domain with an empty memory space and a
> parent domain specified from which to populate the memory when necessary. For
> the new domain to be functional the VM state is copied over as part of the fork
> operation (HVM params, hap allocation, etc).
>
> Signed-off-by: Tamas K Lengyel <tamas.lengyel@intel.com>
> Acked-by: Jan Beulich <jbeulich@suse.com>
> +static int bring_up_vcpus(struct domain *cd, struct domain *d)
> +{
> + unsigned int i;
> + int ret = -EINVAL;
> +
> + if ( d->max_vcpus != cd->max_vcpus ||
> + (ret = cpupool_move_domain(cd, d->cpupool)) )
> + return ret;
> +
> + for ( i = 0; i < cd->max_vcpus; i++ )
> + {
> + if ( !d->vcpu[i] || cd->vcpu[i] )
> + continue;
> +
> + if ( !vcpu_create(cd, i) )
> + return -EINVAL;
> + }
> +
> + domain_update_node_affinity(cd);
> + return 0;
> +}
> +
> +static int copy_vcpu_settings(struct domain *cd, struct domain *d)
Nit: AFAICT *d can be constified.
> +{
> + unsigned int i;
> + struct p2m_domain *p2m = p2m_get_hostp2m(cd);
> + int ret = -EINVAL;
> +
> + for ( i = 0; i < cd->max_vcpus; i++ )
> + {
> + const struct vcpu *d_vcpu = d->vcpu[i];
> + struct vcpu *cd_vcpu = cd->vcpu[i];
> + struct vcpu_runstate_info runstate;
> + mfn_t vcpu_info_mfn;
> +
> + if ( !d_vcpu || !cd_vcpu )
> + continue;
> +
> + /* Copy & map in the vcpu_info page if the guest uses one */
> + vcpu_info_mfn = d_vcpu->vcpu_info_mfn;
> + if ( !mfn_eq(vcpu_info_mfn, INVALID_MFN) )
> + {
> + mfn_t new_vcpu_info_mfn = cd_vcpu->vcpu_info_mfn;
> +
> + /* Allocate & map the page for it if it hasn't been already */
> + if ( mfn_eq(new_vcpu_info_mfn, INVALID_MFN) )
> + {
> + gfn_t gfn = mfn_to_gfn(d, vcpu_info_mfn);
> + unsigned long gfn_l = gfn_x(gfn);
> + struct page_info *page;
> +
> + if ( !(page = alloc_domheap_page(cd, 0)) )
> + return -ENOMEM;
> +
> + new_vcpu_info_mfn = page_to_mfn(page);
> + set_gpfn_from_mfn(mfn_x(new_vcpu_info_mfn), gfn_l);
> +
> + ret = p2m->set_entry(p2m, gfn, new_vcpu_info_mfn,
> + PAGE_ORDER_4K, p2m_ram_rw,
> + p2m->default_access, -1);
> + if ( ret )
> + return ret;
> +
> + ret = map_vcpu_info(cd_vcpu, gfn_l,
> + PAGE_OFFSET(d_vcpu->vcpu_info));
> + if ( ret )
> + return ret;
> + }
> +
> + copy_domain_page(new_vcpu_info_mfn, vcpu_info_mfn);
> + }
> +
> + /* Setup the vCPU runstate area */
> + if ( !guest_handle_is_null(runstate_guest(d_vcpu)) )
> + {
> + runstate_guest(cd_vcpu) = runstate_guest(d_vcpu);
> + vcpu_runstate_get(cd_vcpu, &runstate);
> + __copy_to_guest(runstate_guest(cd_vcpu), &runstate, 1);
I just realized there's no need to copy the runstate area contents
here, since they will get copied anyway in schedule_tail before
resuming execution og cd_vcpu as long as runstate_guest is set.
Note that the vcpu_info needs to be copied since it contains event
channel info which is not unconditionally updated on context switch
IIRC.
> + }
> +
> + /*
> + * TODO: to support VMs with PV interfaces copy additional
> + * settings here, such as PV timers.
> + */
> + }
> +
> + return 0;
> +}
> +
> +static int fork_hap_allocation(struct domain *cd, struct domain *d)
> +{
> + int rc;
> + bool preempted;
> + unsigned long mb = hap_get_allocation(d);
> +
> + if ( mb == hap_get_allocation(cd) )
> + return 0;
> +
> + paging_lock(cd);
> + rc = hap_set_allocation(cd, mb << (20 - PAGE_SHIFT), &preempted);
> + paging_unlock(cd);
> +
> + return preempted ? -ERESTART : rc;
> +}
> +
> +static void copy_tsc(struct domain *cd, struct domain *d)
> +{
> + uint32_t tsc_mode;
> + uint32_t gtsc_khz;
> + uint32_t incarnation;
> + uint64_t elapsed_nsec;
> +
> + tsc_get_info(d, &tsc_mode, &elapsed_nsec, >sc_khz, &incarnation);
> + /* Don't bump incarnation on set */
> + tsc_set_info(cd, tsc_mode, elapsed_nsec, gtsc_khz, incarnation - 1);
> +}
> +
> +static int copy_special_pages(struct domain *cd, struct domain *d)
> +{
> + mfn_t new_mfn, old_mfn;
> + struct p2m_domain *p2m = p2m_get_hostp2m(cd);
> + static const unsigned int params[] =
> + {
> + HVM_PARAM_STORE_PFN,
> + HVM_PARAM_IOREQ_PFN,
> + HVM_PARAM_BUFIOREQ_PFN,
> + HVM_PARAM_CONSOLE_PFN
> + };
> + unsigned int i;
> + int rc;
> +
> + for ( i = 0; i < ARRAY_SIZE(params); i++ )
> + {
> + p2m_type_t t;
> + uint64_t value = 0;
> + struct page_info *page;
> +
> + if ( hvm_get_param(cd, params[i], &value) || !value )
Don't you need to use d here instead of cd? You want to check whether
the parent has this parameter set in order to copy it to the child I
think.
With that:
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Thanks, Roger.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v13 1/3] xen/mem_sharing: VM forking
2020-04-06 10:52 ` Roger Pau Monné
@ 2020-04-06 14:07 ` Tamas K Lengyel
0 siblings, 0 replies; 7+ messages in thread
From: Tamas K Lengyel @ 2020-04-06 14:07 UTC (permalink / raw)
To: Roger Pau Monné
Cc: Julien Grall, Stefano Stabellini, Tamas K Lengyel, Wei Liu,
Andrew Cooper, Ian Jackson, George Dunlap, Jan Beulich, Xen-devel,
Volodymyr Babchuk
On Mon, Apr 6, 2020 at 4:52 AM Roger Pau Monné <roger.pau@citrix.com> wrote:
>
> On Mon, Mar 30, 2020 at 08:02:08AM -0700, Tamas K Lengyel wrote:
> > VM forking is the process of creating a domain with an empty memory space and a
> > parent domain specified from which to populate the memory when necessary. For
> > the new domain to be functional the VM state is copied over as part of the fork
> > operation (HVM params, hap allocation, etc).
> >
> > Signed-off-by: Tamas K Lengyel <tamas.lengyel@intel.com>
> > Acked-by: Jan Beulich <jbeulich@suse.com>
> > +static int bring_up_vcpus(struct domain *cd, struct domain *d)
> > +{
> > + unsigned int i;
> > + int ret = -EINVAL;
> > +
> > + if ( d->max_vcpus != cd->max_vcpus ||
> > + (ret = cpupool_move_domain(cd, d->cpupool)) )
> > + return ret;
> > +
> > + for ( i = 0; i < cd->max_vcpus; i++ )
> > + {
> > + if ( !d->vcpu[i] || cd->vcpu[i] )
> > + continue;
> > +
> > + if ( !vcpu_create(cd, i) )
> > + return -EINVAL;
> > + }
> > +
> > + domain_update_node_affinity(cd);
> > + return 0;
> > +}
> > +
> > +static int copy_vcpu_settings(struct domain *cd, struct domain *d)
>
> Nit: AFAICT *d can be constified.
Sure.
>
> > +{
> > + unsigned int i;
> > + struct p2m_domain *p2m = p2m_get_hostp2m(cd);
> > + int ret = -EINVAL;
> > +
> > + for ( i = 0; i < cd->max_vcpus; i++ )
> > + {
> > + const struct vcpu *d_vcpu = d->vcpu[i];
> > + struct vcpu *cd_vcpu = cd->vcpu[i];
> > + struct vcpu_runstate_info runstate;
> > + mfn_t vcpu_info_mfn;
> > +
> > + if ( !d_vcpu || !cd_vcpu )
> > + continue;
> > +
> > + /* Copy & map in the vcpu_info page if the guest uses one */
> > + vcpu_info_mfn = d_vcpu->vcpu_info_mfn;
> > + if ( !mfn_eq(vcpu_info_mfn, INVALID_MFN) )
> > + {
> > + mfn_t new_vcpu_info_mfn = cd_vcpu->vcpu_info_mfn;
> > +
> > + /* Allocate & map the page for it if it hasn't been already */
> > + if ( mfn_eq(new_vcpu_info_mfn, INVALID_MFN) )
> > + {
> > + gfn_t gfn = mfn_to_gfn(d, vcpu_info_mfn);
> > + unsigned long gfn_l = gfn_x(gfn);
> > + struct page_info *page;
> > +
> > + if ( !(page = alloc_domheap_page(cd, 0)) )
> > + return -ENOMEM;
> > +
> > + new_vcpu_info_mfn = page_to_mfn(page);
> > + set_gpfn_from_mfn(mfn_x(new_vcpu_info_mfn), gfn_l);
> > +
> > + ret = p2m->set_entry(p2m, gfn, new_vcpu_info_mfn,
> > + PAGE_ORDER_4K, p2m_ram_rw,
> > + p2m->default_access, -1);
> > + if ( ret )
> > + return ret;
> > +
> > + ret = map_vcpu_info(cd_vcpu, gfn_l,
> > + PAGE_OFFSET(d_vcpu->vcpu_info));
> > + if ( ret )
> > + return ret;
> > + }
> > +
> > + copy_domain_page(new_vcpu_info_mfn, vcpu_info_mfn);
> > + }
> > +
> > + /* Setup the vCPU runstate area */
> > + if ( !guest_handle_is_null(runstate_guest(d_vcpu)) )
> > + {
> > + runstate_guest(cd_vcpu) = runstate_guest(d_vcpu);
> > + vcpu_runstate_get(cd_vcpu, &runstate);
> > + __copy_to_guest(runstate_guest(cd_vcpu), &runstate, 1);
>
> I just realized there's no need to copy the runstate area contents
> here, since they will get copied anyway in schedule_tail before
> resuming execution og cd_vcpu as long as runstate_guest is set.
>
> Note that the vcpu_info needs to be copied since it contains event
> channel info which is not unconditionally updated on context switch
> IIRC.
OK
>
> > + }
> > +
> > + /*
> > + * TODO: to support VMs with PV interfaces copy additional
> > + * settings here, such as PV timers.
> > + */
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int fork_hap_allocation(struct domain *cd, struct domain *d)
> > +{
> > + int rc;
> > + bool preempted;
> > + unsigned long mb = hap_get_allocation(d);
> > +
> > + if ( mb == hap_get_allocation(cd) )
> > + return 0;
> > +
> > + paging_lock(cd);
> > + rc = hap_set_allocation(cd, mb << (20 - PAGE_SHIFT), &preempted);
> > + paging_unlock(cd);
> > +
> > + return preempted ? -ERESTART : rc;
> > +}
> > +
> > +static void copy_tsc(struct domain *cd, struct domain *d)
> > +{
> > + uint32_t tsc_mode;
> > + uint32_t gtsc_khz;
> > + uint32_t incarnation;
> > + uint64_t elapsed_nsec;
> > +
> > + tsc_get_info(d, &tsc_mode, &elapsed_nsec, >sc_khz, &incarnation);
> > + /* Don't bump incarnation on set */
> > + tsc_set_info(cd, tsc_mode, elapsed_nsec, gtsc_khz, incarnation - 1);
> > +}
> > +
> > +static int copy_special_pages(struct domain *cd, struct domain *d)
> > +{
> > + mfn_t new_mfn, old_mfn;
> > + struct p2m_domain *p2m = p2m_get_hostp2m(cd);
> > + static const unsigned int params[] =
> > + {
> > + HVM_PARAM_STORE_PFN,
> > + HVM_PARAM_IOREQ_PFN,
> > + HVM_PARAM_BUFIOREQ_PFN,
> > + HVM_PARAM_CONSOLE_PFN
> > + };
> > + unsigned int i;
> > + int rc;
> > +
> > + for ( i = 0; i < ARRAY_SIZE(params); i++ )
> > + {
> > + p2m_type_t t;
> > + uint64_t value = 0;
> > + struct page_info *page;
> > +
> > + if ( hvm_get_param(cd, params[i], &value) || !value )
>
> Don't you need to use d here instead of cd? You want to check whether
> the parent has this parameter set in order to copy it to the child I
> think.
Indeed, I probably made this error in one of the revisions when I
renamed the variable.
>
> With that:
>
> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
Thanks,
Tamas
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2020-04-06 14:08 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2020-03-30 15:02 [Xen-devel] [PATCH v13 0/3] VM forking Tamas K Lengyel
2020-03-30 15:02 ` [Xen-devel] [PATCH v13 1/3] xen/mem_sharing: " Tamas K Lengyel
2020-03-31 10:09 ` Julien Grall
2020-04-06 10:52 ` Roger Pau Monné
2020-04-06 14:07 ` Tamas K Lengyel
2020-03-30 15:02 ` [Xen-devel] [PATCH v13 2/3] x86/mem_sharing: reset a fork Tamas K Lengyel
2020-03-30 15:02 ` [Xen-devel] [PATCH v13 3/3] xen/tools: VM forking toolstack side Tamas K Lengyel
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