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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 11/11] x86/altp2m: alternate p2m memory events.
Add a flag to indicate that a memory event occurred in an alternate p2m
and a field containing the p2m index. Allow the response to switch to
a different p2m using the same flag and field.
Modify p2m_access_check() to handle alternate p2m's. Access_required is
always assumed for an alternate p2m.
Signed-off-by: Ed White <edmund.h.white@xxxxxxxxx>
---
xen/arch/x86/mm/hap/altp2m_hap.c | 53 ++++++++++++++++++++++++++++++++++++++--
xen/arch/x86/mm/p2m.c | 18 ++++++++++++--
xen/common/mem_access.c | 1 +
xen/include/asm-arm/p2m.h | 7 ++++++
xen/include/asm-x86/p2m.h | 4 +++
xen/include/public/mem_event.h | 9 +++++++
6 files changed, 88 insertions(+), 4 deletions(-)
diff --git a/xen/arch/x86/mm/hap/altp2m_hap.c b/xen/arch/x86/mm/hap/altp2m_hap.c
index b889626..dd56bbc 100644
--- a/xen/arch/x86/mm/hap/altp2m_hap.c
+++ b/xen/arch/x86/mm/hap/altp2m_hap.c
@@ -19,6 +19,7 @@
*/
#include <xen/mem_event.h>
+#include <xen/mem_access.h>
#include <xen/event.h>
#include <public/mem_event.h>
#include <asm/domain.h>
@@ -63,8 +64,9 @@ altp2m_write_p2m_entry(struct p2m_domain *p2m, unsigned long
gfn,
* else indicate that outer handler should handle fault
*
* If the fault is for a present entry:
- * if the page type is not p2m_ram_rw_ve crash domain
- * else if hardware does not support #VE emulate it and retry
+ * if the page type is p2m_ram_rw_ve and hardware does not support #VE
+ * emulate #VE and retry if successful
+ * else try to send a memory event
* else crash domain
*/
@@ -90,11 +92,58 @@ altp2mhvm_hap_nested_page_fault(struct vcpu *v, paddr_t gpa,
if ( mfn_valid(mfn) )
{
+ bool_t violation;
+ mem_event_request_t *req_ptr = NULL;
+
/* Should #VE be emulated for this fault? */
if ( p2mt == p2m_ram_rw_ve && !cpu_has_vmx_virt_exceptions &&
ahvm_vcpu_emulate_ve(v) )
return ALTP2MHVM_PAGEFAULT_DONE;
+ /* Fault not handled yet, so try for mem_event */
+ switch (p2ma)
+ {
+ case p2m_access_n:
+ case p2m_access_n2rwx:
+ default:
+ violation = npfec.read_access || npfec.write_access ||
npfec.insn_fetch;
+ break;
+ case p2m_access_r:
+ violation = npfec.write_access || npfec.insn_fetch;
+ break;
+ case p2m_access_w:
+ violation = npfec.read_access || npfec.insn_fetch;
+ break;
+ case p2m_access_x:
+ violation = npfec.read_access || npfec.write_access;
+ break;
+ case p2m_access_rx:
+ case p2m_access_rx2rw:
+ violation = npfec.write_access;
+ break;
+ case p2m_access_wx:
+ violation = npfec.read_access;
+ break;
+ case p2m_access_rw:
+ violation = npfec.insn_fetch;
+ break;
+ case p2m_access_rwx:
+ violation = 0;
+ break;
+ }
+
+ if ( violation )
+ {
+ p2m_mem_access_check(gpa, gla, npfec, &req_ptr);
+
+ if ( req_ptr )
+ {
+ mem_access_send_req(v->domain, req_ptr);
+ xfree(req_ptr);
+ return ALTP2MHVM_PAGEFAULT_DONE;
+ }
+ }
+
/* Could not handle fault here */
gdprintk(XENLOG_INFO, "Altp2m memory access permissions failure, "
"no mem_event listener VCPU %d, dom %d\n",
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 843a433..d296c8f 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -1486,6 +1486,13 @@ void p2m_mem_event_emulate_check(struct vcpu *v, const
mem_event_response_t *rsp
}
}
+void p2m_mem_event_altp2m_check(struct vcpu *v, const mem_event_response_t
*rsp)
+{
+ if ( (rsp->flags & MEM_EVENT_FLAG_ALTERNATE_P2M) &&
+ altp2mhvm_active(v->domain) )
+ p2m_switch_vcpu_altp2m_by_id(v, rsp->altp2m_idx);
+}
+
void p2m_setup_introspection(struct domain *d)
{
if ( hvm_funcs.enable_msr_exit_interception )
@@ -1502,7 +1509,8 @@ bool_t p2m_mem_access_check(paddr_t gpa, unsigned long
gla,
struct vcpu *v = current;
unsigned long gfn = gpa >> PAGE_SHIFT;
struct domain *d = v->domain;
- struct p2m_domain* p2m = p2m_get_hostp2m(d);
+ struct p2m_domain *p2m = altp2mhvm_active(v->domain) ?
+ p2m_get_altp2m(v) : p2m_get_hostp2m(d);
mfn_t mfn;
p2m_type_t p2mt;
p2m_access_t p2ma;
@@ -1536,7 +1544,7 @@ bool_t p2m_mem_access_check(paddr_t gpa, unsigned long
gla,
if ( !mem_event_check_ring(&d->mem_event->access) || !req_ptr )
{
/* No listener */
- if ( p2m->access_required )
+ if ( p2m->access_required || altp2mhvm_active(v->domain) )
{
gdprintk(XENLOG_INFO, "Memory access permissions failure, "
"no mem_event listener VCPU %d, dom %d\n",
@@ -1612,6 +1620,12 @@ bool_t p2m_mem_access_check(paddr_t gpa, unsigned long
gla,
req->vcpu_id = v->vcpu_id;
p2m_mem_event_fill_regs(req);
+
+ if ( altp2mhvm_active(v->domain) )
+ {
+ req->flags |= MEM_EVENT_FLAG_ALTERNATE_P2M;
+ req->altp2m_idx = vcpu_altp2mhvm(v).p2midx;
+ }
}
/* Pause the current VCPU */
diff --git a/xen/common/mem_access.c b/xen/common/mem_access.c
index d8aac5f..223d048 100644
--- a/xen/common/mem_access.c
+++ b/xen/common/mem_access.c
@@ -48,6 +48,7 @@ void mem_access_resume(struct domain *d)
v = d->vcpu[rsp.vcpu_id];
p2m_mem_event_emulate_check(v, &rsp);
+ p2m_mem_event_altp2m_check(v, &rsp);
/* Unpause domain. */
if ( rsp.flags & MEM_EVENT_FLAG_VCPU_PAUSED )
diff --git a/xen/include/asm-arm/p2m.h b/xen/include/asm-arm/p2m.h
index da36504..c838f26 100644
--- a/xen/include/asm-arm/p2m.h
+++ b/xen/include/asm-arm/p2m.h
@@ -78,6 +78,13 @@ void p2m_mem_event_emulate_check(struct vcpu *v,
};
static inline
+void p2m_mem_event_altp2m_check(struct vcpu *v,
+ const mem_event_response_t *rsp)
+{
+ /* Not supported on ARM. */
+};
+
+static inline
void p2m_setup_introspection(struct domain *d)
{
/* No special setup on ARM. */
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index 52588ed..e4bc64f 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -737,6 +737,10 @@ bool_t p2m_change_altp2m_pfn(struct domain *d, uint16_t
idx,
/* Invalidate a page in all alternate p2m's */
void p2m_remove_altp2m_page(struct domain *d, unsigned long gfn);
+/* Check to see if vcpu should be switched to a different p2m. */
+void p2m_mem_event_altp2m_check(struct vcpu *v,
+ const mem_event_response_t *rsp);
+
/*
* p2m type to IOMMU flags
*/
diff --git a/xen/include/public/mem_event.h b/xen/include/public/mem_event.h
index 599f9e8..b877899 100644
--- a/xen/include/public/mem_event.h
+++ b/xen/include/public/mem_event.h
@@ -47,6 +47,14 @@
* potentially having side effects (like memory mapped or port I/O) disabled.
*/
#define MEM_EVENT_FLAG_EMULATE_NOWRITE (1 << 6)
+/*
+ * On a request, indicates that the event occurred in the alternate p2m
specified by
+ * the altp2m_idx request field.
+ *
+ * On a response, indicates that the VCPU should resume in the alternate p2m
specified
+ * by the altp2m_idx response field if possible.
+ */
+#define MEM_EVENT_FLAG_ALTERNATE_P2M (1 << 7)
/* Reasons for the memory event request */
#define MEM_EVENT_REASON_UNKNOWN 0 /* typical reason */
@@ -117,6 +125,7 @@ typedef struct mem_event_st {
uint16_t reason;
struct mem_event_regs_x86 x86_regs;
+ uint16_t altp2m_idx;
} mem_event_request_t, mem_event_response_t;
DEFINE_RING_TYPES(mem_event, mem_event_request_t, mem_event_response_t);
--
1.9.1
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