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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] IOREQ: refine when to send mapcache invalidation request
commit 588d961d15d1af5b51d7c33b5278ac7269a961ef
Author: Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Thu Feb 18 13:11:19 2021 +0100
Commit: Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Feb 18 13:11:19 2021 +0100
IOREQ: refine when to send mapcache invalidation request
XENMEM_decrease_reservation isn't the only means by which pages can get
removed from a guest, yet all removals ought to be signaled to qemu. Put
setting of the flag into the central p2m_remove_page() underlying all
respective hypercalls as well as a few similar places, mainly in PoD
code.
Additionally there's no point sending the request for the local domain
when the domain acted upon is a different one. The latter domain's ioreq
server mapcaches need invalidating. We assume that domain to be paused
at the point the operation takes place, so sending the request in this
case happens from the hvm_do_resume() path, which as one of its first
steps calls handle_hvm_io_completion().
Even without the remote operation aspect a single domain-wide flag
doesn't do: Guests may e.g. decrease-reservation on multiple vCPU-s in
parallel. Each of them needs to issue an invalidation request in due
course, in particular because exiting to guest context should not happen
before the request was actually seen by (all) the emulator(s).
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Paul Durrant <paul@xxxxxxx>
Acked-by: Julien Grall <jgrall@xxxxxxxxxx>
---
xen/arch/arm/p2m.c | 7 +++----
xen/arch/arm/traps.c | 4 ++--
xen/arch/x86/hvm/hypercall.c | 12 +++++-------
xen/arch/x86/mm/p2m-pod.c | 9 +++++++++
xen/arch/x86/mm/p2m.c | 5 +++++
xen/common/ioreq.c | 32 +++++++++++++++++++++++++++-----
xen/include/xen/ioreq.h | 1 +
xen/include/xen/sched.h | 13 ++++++++-----
8 files changed, 60 insertions(+), 23 deletions(-)
diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 6895804379..ac50312620 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -759,10 +759,9 @@ static void p2m_free_entry(struct p2m_domain *p2m,
* has failed (error case).
* So, at worst, the spurious mapcache invalidation might be sent.
*/
- if ( (p2m->domain == current->domain) &&
- domain_has_ioreq_server(p2m->domain) &&
- p2m_is_ram(entry.p2m.type) )
- p2m->domain->mapcache_invalidate = true;
+ if ( p2m_is_ram(entry.p2m.type) &&
+ domain_has_ioreq_server(p2m->domain) )
+ ioreq_request_mapcache_invalidate(p2m->domain);
#endif
p2m->stats.mappings[level]--;
diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index 6fa135050b..ccc0827107 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -1509,8 +1509,8 @@ static void do_trap_hypercall(struct cpu_user_regs *regs,
register_t *nr,
* Note that sending the invalidation request causes the vCPU to block
* until all the IOREQ servers have acknowledged the invalidation.
*/
- if ( unlikely(curr->domain->mapcache_invalidate) &&
- test_and_clear_bool(curr->domain->mapcache_invalidate) )
+ if ( unlikely(curr->mapcache_invalidate) &&
+ test_and_clear_bool(curr->mapcache_invalidate) )
ioreq_signal_mapcache_invalidate();
#endif
}
diff --git a/xen/arch/x86/hvm/hypercall.c b/xen/arch/x86/hvm/hypercall.c
index 6d41c563e1..b084afcbce 100644
--- a/xen/arch/x86/hvm/hypercall.c
+++ b/xen/arch/x86/hvm/hypercall.c
@@ -32,7 +32,6 @@
static long hvm_memory_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
{
- const struct vcpu *curr = current;
long rc;
switch ( cmd & MEMOP_CMD_MASK )
@@ -42,14 +41,11 @@ static long hvm_memory_op(int cmd,
XEN_GUEST_HANDLE_PARAM(void) arg)
return -ENOSYS;
}
- if ( !curr->hcall_compat )
+ if ( !current->hcall_compat )
rc = do_memory_op(cmd, arg);
else
rc = compat_memory_op(cmd, arg);
- if ( (cmd & MEMOP_CMD_MASK) == XENMEM_decrease_reservation )
- curr->domain->mapcache_invalidate = true;
-
return rc;
}
@@ -327,9 +323,11 @@ int hvm_hypercall(struct cpu_user_regs *regs)
HVM_DBG_LOG(DBG_LEVEL_HCALL, "hcall%lu -> %lx", eax, regs->rax);
- if ( unlikely(currd->mapcache_invalidate) &&
- test_and_clear_bool(currd->mapcache_invalidate) )
+ if ( unlikely(curr->mapcache_invalidate) )
+ {
+ curr->mapcache_invalidate = false;
ioreq_signal_mapcache_invalidate();
+ }
return curr->hcall_preempted ? HVM_HCALL_preempted : HVM_HCALL_completed;
}
diff --git a/xen/arch/x86/mm/p2m-pod.c b/xen/arch/x86/mm/p2m-pod.c
index 48e609d1ed..ae153fa6e6 100644
--- a/xen/arch/x86/mm/p2m-pod.c
+++ b/xen/arch/x86/mm/p2m-pod.c
@@ -20,6 +20,7 @@
*/
#include <xen/event.h>
+#include <xen/ioreq.h>
#include <xen/mm.h>
#include <xen/sched.h>
#include <xen/trace.h>
@@ -647,6 +648,8 @@ p2m_pod_decrease_reservation(struct domain *d, gfn_t gfn,
unsigned int order)
set_gpfn_from_mfn(mfn_x(mfn), INVALID_M2P_ENTRY);
p2m_pod_cache_add(p2m, page, cur_order);
+ ioreq_request_mapcache_invalidate(d);
+
steal_for_cache = ( p2m->pod.entry_count > p2m->pod.count );
ram -= n;
@@ -835,6 +838,8 @@ p2m_pod_zero_check_superpage(struct p2m_domain *p2m, gfn_t
gfn)
p2m_pod_cache_add(p2m, mfn_to_page(mfn0), PAGE_ORDER_2M);
p2m->pod.entry_count += SUPERPAGE_PAGES;
+ ioreq_request_mapcache_invalidate(d);
+
ret = SUPERPAGE_PAGES;
out_reset:
@@ -997,6 +1002,8 @@ p2m_pod_zero_check(struct p2m_domain *p2m, const gfn_t
*gfns, unsigned int count
/* Add to cache, and account for the new p2m PoD entry */
p2m_pod_cache_add(p2m, mfn_to_page(mfns[i]), PAGE_ORDER_4K);
p2m->pod.entry_count++;
+
+ ioreq_request_mapcache_invalidate(d);
}
}
@@ -1315,6 +1322,8 @@ guest_physmap_mark_populate_on_demand(struct domain *d,
unsigned long gfn_l,
p2m->pod.entry_count -= pod_count;
BUG_ON(p2m->pod.entry_count < 0);
pod_unlock(p2m);
+
+ ioreq_request_mapcache_invalidate(d);
}
out:
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 2091aed4a6..3840f167b0 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -28,6 +28,7 @@
#include <xen/vm_event.h>
#include <xen/event.h>
#include <xen/grant_table.h>
+#include <xen/ioreq.h>
#include <xen/param.h>
#include <public/vm_event.h>
#include <asm/domain.h>
@@ -815,6 +816,8 @@ p2m_remove_page(struct p2m_domain *p2m, gfn_t gfn, mfn_t
mfn,
}
}
+ ioreq_request_mapcache_invalidate(p2m->domain);
+
return p2m_set_entry(p2m, gfn, INVALID_MFN, page_order, p2m_invalid,
p2m->default_access);
}
@@ -1301,6 +1304,8 @@ static int set_typed_p2m_entry(struct domain *d, unsigned
long gfn_l,
ASSERT(mfn_valid(mfn_add(omfn, i)));
set_gpfn_from_mfn(mfn_x(omfn) + i, INVALID_M2P_ENTRY);
}
+
+ ioreq_request_mapcache_invalidate(d);
}
P2M_DEBUG("set %d %lx %lx\n", gfn_p2mt, gfn_l, mfn_x(mfn));
diff --git a/xen/common/ioreq.c b/xen/common/ioreq.c
index 5b603c0520..d732dc045d 100644
--- a/xen/common/ioreq.c
+++ b/xen/common/ioreq.c
@@ -35,6 +35,17 @@
#include <public/hvm/ioreq.h>
#include <public/hvm/params.h>
+void ioreq_request_mapcache_invalidate(const struct domain *d)
+{
+ struct vcpu *v = current;
+
+ if ( d == v->domain )
+ v->mapcache_invalidate = true;
+ else if ( d->creation_finished )
+ for_each_vcpu ( d, v )
+ v->mapcache_invalidate = true;
+}
+
/* Ask ioemu mapcache to invalidate mappings. */
void ioreq_signal_mapcache_invalidate(void)
{
@@ -206,6 +217,7 @@ bool vcpu_ioreq_handle_completion(struct vcpu *v)
struct ioreq_server *s;
struct ioreq_vcpu *sv;
enum vio_completion completion;
+ bool res = true;
if ( has_vpci(d) && vpci_process_pending(v) )
{
@@ -232,17 +244,27 @@ bool vcpu_ioreq_handle_completion(struct vcpu *v)
break;
case VIO_mmio_completion:
- return arch_ioreq_complete_mmio();
+ res = arch_ioreq_complete_mmio();
+ break;
case VIO_pio_completion:
- return handle_pio(vio->req.addr, vio->req.size,
- vio->req.dir);
+ res = handle_pio(vio->req.addr, vio->req.size,
+ vio->req.dir);
+ break;
default:
- return arch_vcpu_ioreq_completion(completion);
+ res = arch_vcpu_ioreq_completion(completion);
+ break;
}
- return true;
+ if ( res && unlikely(v->mapcache_invalidate) )
+ {
+ v->mapcache_invalidate = false;
+ ioreq_signal_mapcache_invalidate();
+ res = false;
+ }
+
+ return res;
}
static int ioreq_server_alloc_mfn(struct ioreq_server *s, bool buf)
diff --git a/xen/include/xen/ioreq.h b/xen/include/xen/ioreq.h
index a54a637bef..a26614d331 100644
--- a/xen/include/xen/ioreq.h
+++ b/xen/include/xen/ioreq.h
@@ -103,6 +103,7 @@ struct ioreq_server *ioreq_server_select(struct domain *d,
int ioreq_send(struct ioreq_server *s, ioreq_t *proto_p,
bool buffered);
unsigned int ioreq_broadcast(ioreq_t *p, bool buffered);
+void ioreq_request_mapcache_invalidate(const struct domain *d);
void ioreq_signal_mapcache_invalidate(void);
void ioreq_domain_init(struct domain *d);
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index bc78a09a53..5485d08afb 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -225,6 +225,14 @@ struct vcpu
bool hcall_compat;
#endif
+#ifdef CONFIG_IOREQ_SERVER
+ /*
+ * Indicates that mapcache invalidation request should be sent to
+ * the device emulator.
+ */
+ bool mapcache_invalidate;
+#endif
+
/* The CPU, if any, which is holding onto this VCPU's state. */
#define VCPU_CPU_CLEAN (~0u)
unsigned int dirty_cpu;
@@ -448,11 +456,6 @@ struct domain
* unpaused for the first time by the systemcontroller.
*/
bool creation_finished;
- /*
- * Indicates that mapcache invalidation request should be sent to
- * the device emulator.
- */
- bool mapcache_invalidate;
/* Which guest this guest has privileges on */
struct domain *target;
--
generated by git-patchbot for /home/xen/git/xen.git#staging
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