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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v4 2/8] ioreq-server: centralize access to ioreq structures
To simplify creation of the ioreq server abstraction in a subsequent patch,
this patch centralizes all use of the shared ioreq structure and the
buffered ioreq ring to the source module xen/arch/x86/hvm/hvm.c.
The patch moves an rmb() from inside hvm_io_assist() to hvm_do_resume()
because the former may now be passed a data structure on stack, in which
case the barrier is unnecessary.
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
Cc: Keir Fraser <keir@xxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Jun Nakajima <jun.nakajima@xxxxxxxxx>
Cc: Eddie Dong <eddie.dong@xxxxxxxxx>
Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
---
xen/arch/x86/hvm/emulate.c | 70 +++++++++-------------
xen/arch/x86/hvm/hvm.c | 118 +++++++++++++++++++++++++++++++++++--
xen/arch/x86/hvm/io.c | 104 +++-----------------------------
xen/arch/x86/hvm/vmx/vvmx.c | 13 +++-
xen/include/asm-x86/hvm/hvm.h | 15 ++++-
xen/include/asm-x86/hvm/support.h | 21 ++++---
6 files changed, 185 insertions(+), 156 deletions(-)
diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c
index 868aa1d..1c71902 100644
--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -57,24 +57,11 @@ static int hvmemul_do_io(
int value_is_ptr = (p_data == NULL);
struct vcpu *curr = current;
struct hvm_vcpu_io *vio;
- ioreq_t *p = get_ioreq(curr);
- ioreq_t _ioreq;
+ ioreq_t p;
unsigned long ram_gfn = paddr_to_pfn(ram_gpa);
p2m_type_t p2mt;
struct page_info *ram_page;
int rc;
- bool_t has_dm = 1;
-
- /*
- * Domains without a backing DM, don't have an ioreq page. Just
- * point to a struct on the stack, initialising the state as needed.
- */
- if ( !p )
- {
- has_dm = 0;
- p = &_ioreq;
- p->state = STATE_IOREQ_NONE;
- }
/* Check for paged out page */
ram_page = get_page_from_gfn(curr->domain, ram_gfn, &p2mt, P2M_UNSHARE);
@@ -173,15 +160,6 @@ static int hvmemul_do_io(
return X86EMUL_UNHANDLEABLE;
}
- if ( p->state != STATE_IOREQ_NONE )
- {
- gdprintk(XENLOG_WARNING, "WARNING: io already pending (%d)?\n",
- p->state);
- if ( ram_page )
- put_page(ram_page);
- return X86EMUL_UNHANDLEABLE;
- }
-
vio->io_state =
(p_data == NULL) ? HVMIO_dispatched : HVMIO_awaiting_completion;
vio->io_size = size;
@@ -193,38 +171,38 @@ static int hvmemul_do_io(
if ( vio->mmio_retrying )
*reps = 1;
- p->dir = dir;
- p->data_is_ptr = value_is_ptr;
- p->type = is_mmio ? IOREQ_TYPE_COPY : IOREQ_TYPE_PIO;
- p->size = size;
- p->addr = addr;
- p->count = *reps;
- p->df = df;
- p->data = value;
+ p.dir = dir;
+ p.data_is_ptr = value_is_ptr;
+ p.type = is_mmio ? IOREQ_TYPE_COPY : IOREQ_TYPE_PIO;
+ p.size = size;
+ p.addr = addr;
+ p.count = *reps;
+ p.df = df;
+ p.data = value;
if ( dir == IOREQ_WRITE )
- hvmtrace_io_assist(is_mmio, p);
+ hvmtrace_io_assist(is_mmio, &p);
if ( is_mmio )
{
- rc = hvm_mmio_intercept(p);
+ rc = hvm_mmio_intercept(&p);
if ( rc == X86EMUL_UNHANDLEABLE )
- rc = hvm_buffered_io_intercept(p);
+ rc = hvm_buffered_io_intercept(&p);
}
else
{
- rc = hvm_portio_intercept(p);
+ rc = hvm_portio_intercept(&p);
}
switch ( rc )
{
case X86EMUL_OKAY:
case X86EMUL_RETRY:
- *reps = p->count;
- p->state = STATE_IORESP_READY;
+ *reps = p.count;
+ p.state = STATE_IORESP_READY;
if ( !vio->mmio_retry )
{
- hvm_io_assist(p);
+ hvm_io_assist(&p);
vio->io_state = HVMIO_none;
}
else
@@ -233,7 +211,7 @@ static int hvmemul_do_io(
break;
case X86EMUL_UNHANDLEABLE:
/* If there is no backing DM, just ignore accesses */
- if ( !has_dm )
+ if ( !hvm_has_dm(curr->domain) )
{
rc = X86EMUL_OKAY;
vio->io_state = HVMIO_none;
@@ -241,7 +219,7 @@ static int hvmemul_do_io(
else
{
rc = X86EMUL_RETRY;
- if ( !hvm_send_assist_req(curr) )
+ if ( !hvm_send_assist_req(curr, &p) )
vio->io_state = HVMIO_none;
else if ( p_data == NULL )
rc = X86EMUL_OKAY;
@@ -260,7 +238,7 @@ static int hvmemul_do_io(
finish_access:
if ( dir == IOREQ_READ )
- hvmtrace_io_assist(is_mmio, p);
+ hvmtrace_io_assist(is_mmio, &p);
if ( p_data != NULL )
memcpy(p_data, &vio->io_data, size);
@@ -1292,3 +1270,13 @@ struct segment_register *hvmemul_get_seg_reg(
hvm_get_segment_register(current, seg, &hvmemul_ctxt->seg_reg[seg]);
return &hvmemul_ctxt->seg_reg[seg];
}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 69d0a44..573f845 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -352,6 +352,26 @@ void hvm_migrate_pirqs(struct vcpu *v)
spin_unlock(&d->event_lock);
}
+static ioreq_t *get_ioreq(struct vcpu *v)
+{
+ struct domain *d = v->domain;
+ shared_iopage_t *p = d->arch.hvm_domain.ioreq.va;
+
+ ASSERT((v == current) || spin_is_locked(&d->arch.hvm_domain.ioreq.lock));
+
+ return p ? &p->vcpu_ioreq[v->vcpu_id] : NULL;
+}
+
+bool_t hvm_io_pending(struct vcpu *v)
+{
+ ioreq_t *p = get_ioreq(v);
+
+ if ( !p )
+ return 0;
+
+ return ( p->state != STATE_IOREQ_NONE );
+}
+
void hvm_do_resume(struct vcpu *v)
{
ioreq_t *p = get_ioreq(v);
@@ -370,11 +390,12 @@ void hvm_do_resume(struct vcpu *v)
switch ( p->state )
{
case STATE_IORESP_READY: /* IORESP_READY -> NONE */
+ rmb(); /* see IORESP_READY /then/ read contents of ioreq */
hvm_io_assist(p);
break;
case STATE_IOREQ_READY: /* IOREQ_{READY,INPROCESS} -> IORESP_READY */
case STATE_IOREQ_INPROCESS:
- wait_on_xen_event_channel(v->arch.hvm_vcpu.xen_port,
+ wait_on_xen_event_channel(p->vp_eport,
(p->state != STATE_IOREQ_READY) &&
(p->state != STATE_IOREQ_INPROCESS));
break;
@@ -1414,7 +1435,87 @@ void hvm_vcpu_down(struct vcpu *v)
}
}
-bool_t hvm_send_assist_req(struct vcpu *v)
+int hvm_buffered_io_send(struct domain *d, const ioreq_t *p)
+{
+ struct hvm_ioreq_page *iorp = &d->arch.hvm_domain.buf_ioreq;
+ buffered_iopage_t *pg = iorp->va;
+ buf_ioreq_t bp;
+ /* Timeoffset sends 64b data, but no address. Use two consecutive slots. */
+ int qw = 0;
+
+ /* Ensure buffered_iopage fits in a page */
+ BUILD_BUG_ON(sizeof(buffered_iopage_t) > PAGE_SIZE);
+
+ /*
+ * Return 0 for the cases we can't deal with:
+ * - 'addr' is only a 20-bit field, so we cannot address beyond 1MB
+ * - we cannot buffer accesses to guest memory buffers, as the guest
+ * may expect the memory buffer to be synchronously accessed
+ * - the count field is usually used with data_is_ptr and since we don't
+ * support data_is_ptr we do not waste space for the count field either
+ */
+ if ( (p->addr > 0xffffful) || p->data_is_ptr || (p->count != 1) )
+ return 0;
+
+ bp.type = p->type;
+ bp.dir = p->dir;
+ switch ( p->size )
+ {
+ case 1:
+ bp.size = 0;
+ break;
+ case 2:
+ bp.size = 1;
+ break;
+ case 4:
+ bp.size = 2;
+ break;
+ case 8:
+ bp.size = 3;
+ qw = 1;
+ break;
+ default:
+ gdprintk(XENLOG_WARNING, "unexpected ioreq size: %u\n", p->size);
+ return 0;
+ }
+
+ bp.data = p->data;
+ bp.addr = p->addr;
+
+ spin_lock(&iorp->lock);
+
+ if ( (pg->write_pointer - pg->read_pointer) >=
+ (IOREQ_BUFFER_SLOT_NUM - qw) )
+ {
+ /* The queue is full: send the iopacket through the normal path. */
+ spin_unlock(&iorp->lock);
+ return 0;
+ }
+
+ pg->buf_ioreq[pg->write_pointer % IOREQ_BUFFER_SLOT_NUM] = bp;
+
+ if ( qw )
+ {
+ bp.data = p->data >> 32;
+ pg->buf_ioreq[(pg->write_pointer+1) % IOREQ_BUFFER_SLOT_NUM] = bp;
+ }
+
+ /* Make the ioreq_t visible /before/ write_pointer. */
+ wmb();
+ pg->write_pointer += qw ? 2 : 1;
+
+ notify_via_xen_event_channel(d,
d->arch.hvm_domain.params[HVM_PARAM_BUFIOREQ_EVTCHN]);
+ spin_unlock(&iorp->lock);
+
+ return 1;
+}
+
+bool_t hvm_has_dm(struct domain *d)
+{
+ return !!d->arch.hvm_domain.ioreq.va;
+}
+
+bool_t hvm_send_assist_req(struct vcpu *v, const ioreq_t *proto_p)
{
ioreq_t *p = get_ioreq(v);
@@ -1432,14 +1533,23 @@ bool_t hvm_send_assist_req(struct vcpu *v)
return 0;
}
- prepare_wait_on_xen_event_channel(v->arch.hvm_vcpu.xen_port);
+ p->dir = proto_p->dir;
+ p->data_is_ptr = proto_p->data_is_ptr;
+ p->type = proto_p->type;
+ p->size = proto_p->size;
+ p->addr = proto_p->addr;
+ p->count = proto_p->count;
+ p->df = proto_p->df;
+ p->data = proto_p->data;
+
+ prepare_wait_on_xen_event_channel(p->vp_eport);
/*
* Following happens /after/ blocking and setting up ioreq contents.
* prepare_wait_on_xen_event_channel() is an implicit barrier.
*/
p->state = STATE_IOREQ_READY;
- notify_via_xen_event_channel(v->domain, v->arch.hvm_vcpu.xen_port);
+ notify_via_xen_event_channel(v->domain, p->vp_eport);
return 1;
}
diff --git a/xen/arch/x86/hvm/io.c b/xen/arch/x86/hvm/io.c
index 5ba38d2..8db300d 100644
--- a/xen/arch/x86/hvm/io.c
+++ b/xen/arch/x86/hvm/io.c
@@ -46,82 +46,6 @@
#include <xen/iocap.h>
#include <public/hvm/ioreq.h>
-int hvm_buffered_io_send(struct domain *d, const ioreq_t *p)
-{
- struct hvm_ioreq_page *iorp = &d->arch.hvm_domain.buf_ioreq;
- buffered_iopage_t *pg = iorp->va;
- buf_ioreq_t bp;
- /* Timeoffset sends 64b data, but no address. Use two consecutive slots. */
- int qw = 0;
-
- /* Ensure buffered_iopage fits in a page */
- BUILD_BUG_ON(sizeof(buffered_iopage_t) > PAGE_SIZE);
-
- /*
- * Return 0 for the cases we can't deal with:
- * - 'addr' is only a 20-bit field, so we cannot address beyond 1MB
- * - we cannot buffer accesses to guest memory buffers, as the guest
- * may expect the memory buffer to be synchronously accessed
- * - the count field is usually used with data_is_ptr and since we don't
- * support data_is_ptr we do not waste space for the count field either
- */
- if ( (p->addr > 0xffffful) || p->data_is_ptr || (p->count != 1) )
- return 0;
-
- bp.type = p->type;
- bp.dir = p->dir;
- switch ( p->size )
- {
- case 1:
- bp.size = 0;
- break;
- case 2:
- bp.size = 1;
- break;
- case 4:
- bp.size = 2;
- break;
- case 8:
- bp.size = 3;
- qw = 1;
- break;
- default:
- gdprintk(XENLOG_WARNING, "unexpected ioreq size: %u\n", p->size);
- return 0;
- }
-
- bp.data = p->data;
- bp.addr = p->addr;
-
- spin_lock(&iorp->lock);
-
- if ( (pg->write_pointer - pg->read_pointer) >=
- (IOREQ_BUFFER_SLOT_NUM - qw) )
- {
- /* The queue is full: send the iopacket through the normal path. */
- spin_unlock(&iorp->lock);
- return 0;
- }
-
- pg->buf_ioreq[pg->write_pointer % IOREQ_BUFFER_SLOT_NUM] = bp;
-
- if ( qw )
- {
- bp.data = p->data >> 32;
- pg->buf_ioreq[(pg->write_pointer+1) % IOREQ_BUFFER_SLOT_NUM] = bp;
- }
-
- /* Make the ioreq_t visible /before/ write_pointer. */
- wmb();
- pg->write_pointer += qw ? 2 : 1;
-
- notify_via_xen_event_channel(d,
- d->arch.hvm_domain.params[HVM_PARAM_BUFIOREQ_EVTCHN]);
- spin_unlock(&iorp->lock);
-
- return 1;
-}
-
void send_timeoffset_req(unsigned long timeoff)
{
ioreq_t p = {
@@ -143,26 +67,14 @@ void send_timeoffset_req(unsigned long timeoff)
/* Ask ioemu mapcache to invalidate mappings. */
void send_invalidate_req(void)
{
- struct vcpu *v = current;
- ioreq_t *p = get_ioreq(v);
-
- if ( !p )
- return;
-
- if ( p->state != STATE_IOREQ_NONE )
- {
- gdprintk(XENLOG_ERR, "WARNING: send invalidate req with something "
- "already pending (%d)?\n", p->state);
- domain_crash(v->domain);
- return;
- }
-
- p->type = IOREQ_TYPE_INVALIDATE;
- p->size = 4;
- p->dir = IOREQ_WRITE;
- p->data = ~0UL; /* flush all */
+ ioreq_t p = {
+ .type = IOREQ_TYPE_INVALIDATE,
+ .size = 4,
+ .dir = IOREQ_WRITE,
+ .data = ~0UL, /* flush all */
+ };
- (void)hvm_send_assist_req(v);
+ (void)hvm_send_assist_req(current, &p);
}
int handle_mmio(void)
@@ -265,8 +177,6 @@ void hvm_io_assist(ioreq_t *p)
struct hvm_vcpu_io *vio = &curr->arch.hvm_vcpu.hvm_io;
enum hvm_io_state io_state;
- rmb(); /* see IORESP_READY /then/ read contents of ioreq */
-
p->state = STATE_IOREQ_NONE;
io_state = vio->io_state;
diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
index 40167d6..0421623 100644
--- a/xen/arch/x86/hvm/vmx/vvmx.c
+++ b/xen/arch/x86/hvm/vmx/vvmx.c
@@ -1394,7 +1394,6 @@ void nvmx_switch_guest(void)
struct vcpu *v = current;
struct nestedvcpu *nvcpu = &vcpu_nestedhvm(v);
struct cpu_user_regs *regs = guest_cpu_user_regs();
- const ioreq_t *ioreq = get_ioreq(v);
/*
* A pending IO emulation may still be not finished. In this case, no
@@ -1404,7 +1403,7 @@ void nvmx_switch_guest(void)
* don't want to continue as this setup is not implemented nor supported
* as of right now.
*/
- if ( !ioreq || ioreq->state != STATE_IOREQ_NONE )
+ if ( hvm_io_pending(v) )
return;
/*
* a softirq may interrupt us between a virtual vmentry is
@@ -2522,3 +2521,13 @@ void nvmx_set_cr_read_shadow(struct vcpu *v, unsigned
int cr)
/* nvcpu.guest_cr is what L2 write to cr actually. */
__vmwrite(read_shadow_field, v->arch.hvm_vcpu.nvcpu.guest_cr[cr]);
}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index dcc3483..08a62ea 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -26,6 +26,7 @@
#include <asm/hvm/asid.h>
#include <public/domctl.h>
#include <public/hvm/save.h>
+#include <public/hvm/ioreq.h>
#include <asm/mm.h>
/* Interrupt acknowledgement sources. */
@@ -227,7 +228,7 @@ int prepare_ring_for_helper(struct domain *d, unsigned long
gmfn,
struct page_info **_page, void **_va);
void destroy_ring_for_helper(void **_va, struct page_info *page);
-bool_t hvm_send_assist_req(struct vcpu *v);
+bool_t hvm_send_assist_req(struct vcpu *v, const ioreq_t *p);
void hvm_get_guest_pat(struct vcpu *v, u64 *guest_pat);
int hvm_set_guest_pat(struct vcpu *v, u64 guest_pat);
@@ -339,6 +340,8 @@ static inline unsigned long hvm_get_shadow_gs_base(struct
vcpu *v)
void hvm_cpuid(unsigned int input, unsigned int *eax, unsigned int *ebx,
unsigned int *ecx, unsigned int *edx);
void hvm_migrate_timers(struct vcpu *v);
+bool_t hvm_has_dm(struct domain *d);
+bool_t hvm_io_pending(struct vcpu *v);
void hvm_do_resume(struct vcpu *v);
void hvm_migrate_pirqs(struct vcpu *v);
@@ -522,3 +525,13 @@ bool_t nhvm_vmcx_hap_enabled(struct vcpu *v);
enum hvm_intblk nhvm_interrupt_blocked(struct vcpu *v);
#endif /* __ASM_X86_HVM_HVM_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/include/asm-x86/hvm/support.h
b/xen/include/asm-x86/hvm/support.h
index 1dc2f2d..05ef5c5 100644
--- a/xen/include/asm-x86/hvm/support.h
+++ b/xen/include/asm-x86/hvm/support.h
@@ -22,21 +22,10 @@
#define __ASM_X86_HVM_SUPPORT_H__
#include <xen/types.h>
-#include <public/hvm/ioreq.h>
#include <xen/sched.h>
#include <xen/hvm/save.h>
#include <asm/processor.h>
-static inline ioreq_t *get_ioreq(struct vcpu *v)
-{
- struct domain *d = v->domain;
- shared_iopage_t *p = d->arch.hvm_domain.ioreq.va;
-
- ASSERT((v == current) || spin_is_locked(&d->arch.hvm_domain.ioreq.lock));
-
- return p ? &p->vcpu_ioreq[v->vcpu_id] : NULL;
-}
-
#define HVM_DELIVER_NO_ERROR_CODE -1
#ifndef NDEBUG
@@ -144,3 +133,13 @@ int hvm_mov_to_cr(unsigned int cr, unsigned int gpr);
int hvm_mov_from_cr(unsigned int cr, unsigned int gpr);
#endif /* __ASM_X86_HVM_SUPPORT_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
--
1.7.10.4
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