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List: xen-cvs
Subject: [Xen-changelog] [xen master] x86/mem_event: deliver gla fault EPT violation information
From: patchbot () xen ! org
Date: 2014-08-30 13:01:58
Message-ID: E1XNiI2-0007At-5j () xenbits ! xen ! org
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commit 692f3cc7dd05b80dbd027e46372b1c25d7975332
Author: Tamas K Lengyel <tamas.lengyel@zentific.com>
AuthorDate: Thu Aug 28 16:04:05 2014 +0200
Commit: Jan Beulich <jbeulich@suse.com>
CommitDate: Thu Aug 28 16:04:05 2014 +0200
x86/mem_event: deliver gla fault EPT violation information
On Intel EPT the exit qualification generated by a violation also
includes a bit (EPT_GLA_FAULT) which describes the following
information: Set if the access causing the EPT violation is to a
guest-physical address that is the translation of a linear address.
Clear if the access causing the EPT violation is to a paging-structure
entry as part of a page walk or the update of an accessed or dirty bit.
For more information see Table 27-7 in the Intel SDM.
This patch extends the mem_event system to deliver this extra
information, which could be useful for determining the cause of a
violation.
Signed-off-by: Tamas K Lengyel <tamas.lengyel@zentific.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Tim Deegan <tim@xen.org>
---
xen/arch/x86/hvm/svm/svm.c | 8 +++++++-
xen/arch/x86/hvm/vmx/vmx.c | 4 ++++
xen/arch/x86/mm/p2m.c | 5 ++++-
xen/include/asm-x86/hvm/svm/svm.h | 6 ++++++
xen/include/asm-x86/mm.h | 11 +++++++++++
xen/include/public/mem_event.h | 4 +++-
6 files changed, 35 insertions(+), 3 deletions(-)
diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index d29caa1..b5188e6 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -1394,7 +1394,7 @@ const struct hvm_function_table * __init start_svm(void)
}
static void svm_do_nested_pgfault(struct vcpu *v,
- struct cpu_user_regs *regs, uint32_t pfec, paddr_t gpa)
+ struct cpu_user_regs *regs, uint64_t pfec, paddr_t gpa)
{
int ret;
unsigned long gfn = gpa >> PAGE_SHIFT;
@@ -1414,6 +1414,12 @@ static void svm_do_nested_pgfault(struct vcpu *v,
.insn_fetch = !!(pfec & PFEC_insn_fetch)
};
+ /* These bits are mutually exclusive */
+ if ( pfec & NPT_PFEC_with_gla )
+ npfec.kind = npfec_kind_with_gla;
+ else if ( pfec & NPT_PFEC_in_gpt )
+ npfec.kind = npfec_kind_in_gpt;
+
ret = hvm_hap_nested_page_fault(gpa, ~0ul, npfec);
if ( tb_init_done )
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index d8e1475..26b1ad5 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -2391,6 +2391,10 @@ static void ept_handle_violation(unsigned long qualification, paddr_t gpa)
{
__vmread(GUEST_LINEAR_ADDRESS, &gla);
npfec.gla_valid = 1;
+ if( qualification & EPT_GLA_FAULT )
+ npfec.kind = npfec_kind_with_gla;
+ else
+ npfec.kind = npfec_kind_in_gpt;
}
else
gla = ~0ull;
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 1f1f6cd..c2e89e1 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -1405,10 +1405,13 @@ bool_t p2m_mem_access_check(paddr_t gpa, unsigned long gla,
req->offset = gpa & ((1 << PAGE_SHIFT) - 1);
req->gla_valid = npfec.gla_valid;
req->gla = gla;
+ if ( npfec.kind == npfec_kind_with_gla )
+ req->fault_with_gla = 1;
+ else if ( npfec.kind == npfec_kind_in_gpt )
+ req->fault_in_gpt = 1;
req->access_r = npfec.read_access;
req->access_w = npfec.write_access;
req->access_x = npfec.insn_fetch;
-
req->vcpu_id = v->vcpu_id;
}
diff --git a/xen/include/asm-x86/hvm/svm/svm.h b/xen/include/asm-x86/hvm/svm/svm.h
index 1ffe6d6..cb2db3f 100644
--- a/xen/include/asm-x86/hvm/svm/svm.h
+++ b/xen/include/asm-x86/hvm/svm/svm.h
@@ -105,4 +105,10 @@ extern u32 svm_feature_flags;
extern void svm_host_osvw_reset(void);
extern void svm_host_osvw_init(void);
+/* EXITINFO1 fields on NPT faults */
+#define _NPT_PFEC_with_gla 32
+#define NPT_PFEC_with_gla (1UL<<_NPT_PFEC_with_gla)
+#define _NPT_PFEC_in_gpt 33
+#define NPT_PFEC_in_gpt (1UL<<_NPT_PFEC_in_gpt)
+
#endif /* __ASM_X86_HVM_SVM_H__ */
diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
index 1889b25..7b85865 100644
--- a/xen/include/asm-x86/mm.h
+++ b/xen/include/asm-x86/mm.h
@@ -552,6 +552,16 @@ void audit_domains(void);
#endif
/*
+ * Extra fault info types which are used to further describe
+ * the source of an access violation.
+ */
+typedef enum {
+ npfec_kind_unknown, /* must be first */
+ npfec_kind_in_gpt, /* violation in guest page table */
+ npfec_kind_with_gla /* violation with guest linear address */
+} npfec_kind_t;
+
+/*
* Nested page fault exception codes.
*/
struct npfec {
@@ -559,6 +569,7 @@ struct npfec {
unsigned int write_access:1;
unsigned int insn_fetch:1;
unsigned int gla_valid:1;
+ unsigned int kind:2; /* npfec_kind_t */
};
int new_guest_cr3(unsigned long pfn);
diff --git a/xen/include/public/mem_event.h b/xen/include/public/mem_event.h
index 3831b41..fc12697 100644
--- a/xen/include/public/mem_event.h
+++ b/xen/include/public/mem_event.h
@@ -62,7 +62,9 @@ typedef struct mem_event_st {
uint16_t access_w:1;
uint16_t access_x:1;
uint16_t gla_valid:1;
- uint16_t available:12;
+ uint16_t fault_with_gla:1;
+ uint16_t fault_in_gpt:1;
+ uint16_t available:10;
uint16_t reason;
} mem_event_request_t, mem_event_response_t;
--
generated by git-patchbot for /home/xen/git/xen.git#master
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