Discussion:
[Xen-changelog] [xen master] x86/altp2m: Add a subop for obtaining the mem access of a page
p***@xen.org
2018-11-04 04:58:27 UTC
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commit 7559ab7830c3e1594cd73efd3f1acbb171036728
Author: Razvan Cojocaru <***@bitdefender.com>
AuthorDate: Thu Sep 27 10:58:54 2018 +0300
Commit: George Dunlap <***@citrix.com>
CommitDate: Tue Oct 16 17:20:47 2018 +0100

x86/altp2m: Add a subop for obtaining the mem access of a page

Currently there is a subop for setting the memaccess of a page, but not
for consulting it. The new HVMOP_altp2m_get_mem_access adds this
functionality.

Both altp2m get/set mem access functions use the struct
xen_hvm_altp2m_mem_access which has now dropped the `set' part and has
been renamed from xen_hvm_altp2m_set_mem_access.

Signed-off-by: Adrian Pop <***@bitdefender.com>
Signed-off-by: Razvan Cojocaru <***@bitdefender.com>
Acked-by: Wei Liu <***@citrix.com>
Acked-by: Tamas K Lengyel <***@tklengyel.com>
Reviewed-by: George Dunlap <***@citrix.com>
---
tools/libxc/include/xenctrl.h | 3 +++
tools/libxc/xc_altp2m.c | 33 ++++++++++++++++++++++++++++++---
xen/arch/arm/mem_access.c | 7 +++++--
xen/arch/x86/hvm/hvm.c | 30 ++++++++++++++++++++++++------
xen/arch/x86/mm/mem_access.c | 21 ++++++++++++++++++++-
xen/common/mem_access.c | 2 +-
xen/include/public/hvm/hvm_op.h | 21 ++++++++++++++++++++-
xen/include/public/xen-compat.h | 2 +-
xen/include/xen/mem_access.h | 3 ++-
9 files changed, 106 insertions(+), 16 deletions(-)

diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index dad96a95a3..618f3cbdcd 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -1949,6 +1949,9 @@ int xc_altp2m_set_mem_access(xc_interface *handle, uint32_t domid,
int xc_altp2m_set_mem_access_multi(xc_interface *handle, uint32_t domid,
uint16_t view_id, uint8_t *access,
uint64_t *gfns, uint32_t nr);
+int xc_altp2m_get_mem_access(xc_interface *handle, uint32_t domid,
+ uint16_t view_id, xen_pfn_t gfn,
+ xenmem_access_t *access);
int xc_altp2m_change_gfn(xc_interface *handle, uint32_t domid,
uint16_t view_id, xen_pfn_t old_gfn,
xen_pfn_t new_gfn);
diff --git a/tools/libxc/xc_altp2m.c b/tools/libxc/xc_altp2m.c
index be5bfd28ed..844b9f18ce 100644
--- a/tools/libxc/xc_altp2m.c
+++ b/tools/libxc/xc_altp2m.c
@@ -226,9 +226,9 @@ int xc_altp2m_set_mem_access(xc_interface *handle, uint32_t domid,
arg->version = HVMOP_ALTP2M_INTERFACE_VERSION;
arg->cmd = HVMOP_altp2m_set_mem_access;
arg->domain = domid;
- arg->u.set_mem_access.view = view_id;
- arg->u.set_mem_access.hvmmem_access = access;
- arg->u.set_mem_access.gfn = gfn;
+ arg->u.mem_access.view = view_id;
+ arg->u.mem_access.access = access;
+ arg->u.mem_access.gfn = gfn;

rc = xencall2(handle->xcall, __HYPERVISOR_hvm_op, HVMOP_altp2m,
HYPERCALL_BUFFER_AS_ARG(arg));
@@ -303,3 +303,30 @@ int xc_altp2m_set_mem_access_multi(xc_interface *xch, uint32_t domid,

return rc;
}
+
+int xc_altp2m_get_mem_access(xc_interface *handle, uint32_t domid,
+ uint16_t view_id, xen_pfn_t gfn,
+ xenmem_access_t *access)
+{
+ int rc;
+ DECLARE_HYPERCALL_BUFFER(xen_hvm_altp2m_op_t, arg);
+
+ arg = xc_hypercall_buffer_alloc(handle, arg, sizeof(*arg));
+ if ( arg == NULL )
+ return -1;
+
+ arg->version = HVMOP_ALTP2M_INTERFACE_VERSION;
+ arg->cmd = HVMOP_altp2m_get_mem_access;
+ arg->domain = domid;
+ arg->u.mem_access.view = view_id;
+ arg->u.mem_access.gfn = gfn;
+
+ rc = xencall2(handle->xcall, __HYPERVISOR_hvm_op, HVMOP_altp2m,
+ HYPERCALL_BUFFER_AS_ARG(arg));
+
+ if ( !rc )
+ *access = arg->u.mem_access.access;
+
+ xc_hypercall_buffer_free(handle, arg);
+ return rc;
+}
diff --git a/xen/arch/arm/mem_access.c b/xen/arch/arm/mem_access.c
index ba4ec780fd..653d96050d 100644
--- a/xen/arch/arm/mem_access.c
+++ b/xen/arch/arm/mem_access.c
@@ -236,7 +236,7 @@ bool p2m_mem_access_check(paddr_t gpa, vaddr_t gla, const struct npfec npfec)
if ( !p2m->mem_access_enabled )
return true;

- rc = p2m_get_mem_access(v->domain, gaddr_to_gfn(gpa), &xma);
+ rc = p2m_get_mem_access(v->domain, gaddr_to_gfn(gpa), &xma, 0);
if ( rc )
return true;

@@ -441,11 +441,14 @@ long p2m_set_mem_access_multi(struct domain *d,
}

int p2m_get_mem_access(struct domain *d, gfn_t gfn,
- xenmem_access_t *access)
+ xenmem_access_t *access, unsigned int altp2m_idx)
{
int ret;
struct p2m_domain *p2m = p2m_get_hostp2m(d);

+ /* altp2m is not yet implemented on Arm. The altp2m_idx should be 0. */
+ ASSERT(altp2m_idx == 0);
+
p2m_read_lock(p2m);
ret = __p2m_get_mem_access(d, gfn, access);
p2m_read_unlock(p2m);
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 9c105ff056..4e03e067fa 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4469,6 +4469,7 @@ static int do_altp2m_op(
case HVMOP_altp2m_get_suppress_ve:
case HVMOP_altp2m_set_mem_access:
case HVMOP_altp2m_set_mem_access_multi:
+ case HVMOP_altp2m_get_mem_access:
case HVMOP_altp2m_change_gfn:
break;

@@ -4596,8 +4597,8 @@ static int do_altp2m_op(
rc = -EINVAL;
else
{
- gfn_t gfn = _gfn(a.u.set_mem_access.gfn);
- unsigned int altp2m_idx = a.u.set_mem_access.view;
+ gfn_t gfn = _gfn(a.u.mem_access.gfn);
+ unsigned int altp2m_idx = a.u.mem_access.view;
bool suppress_ve = a.u.suppress_ve.suppress_ve;

rc = p2m_set_suppress_ve(d, gfn, suppress_ve, altp2m_idx);
@@ -4623,12 +4624,12 @@ static int do_altp2m_op(
break;

case HVMOP_altp2m_set_mem_access:
- if ( a.u.set_mem_access.pad )
+ if ( a.u.mem_access.pad )
rc = -EINVAL;
else
- rc = p2m_set_mem_access(d, _gfn(a.u.set_mem_access.gfn), 1, 0, 0,
- a.u.set_mem_access.hvmmem_access,
- a.u.set_mem_access.view);
+ rc = p2m_set_mem_access(d, _gfn(a.u.mem_access.gfn), 1, 0, 0,
+ a.u.mem_access.access,
+ a.u.mem_access.view);
break;

case HVMOP_altp2m_set_mem_access_multi:
@@ -4664,6 +4665,23 @@ static int do_altp2m_op(
}
break;

+ case HVMOP_altp2m_get_mem_access:
+ if ( a.u.mem_access.pad )
+ rc = -EINVAL;
+ else
+ {
+ xenmem_access_t access;
+
+ rc = p2m_get_mem_access(d, _gfn(a.u.mem_access.gfn), &access,
+ a.u.mem_access.view);
+ if ( !rc )
+ {
+ a.u.mem_access.access = access;
+ rc = __copy_to_guest(arg, &a, 1) ? -EFAULT : 0;
+ }
+ }
+ break;
+
case HVMOP_altp2m_change_gfn:
if ( a.u.change_gfn.pad1 || a.u.change_gfn.pad2 )
rc = -EINVAL;
diff --git a/xen/arch/x86/mm/mem_access.c b/xen/arch/x86/mm/mem_access.c
index 3d50fe0d41..2b5a6217db 100644
--- a/xen/arch/x86/mm/mem_access.c
+++ b/xen/arch/x86/mm/mem_access.c
@@ -486,10 +486,29 @@ long p2m_set_mem_access_multi(struct domain *d,
return rc;
}

-int p2m_get_mem_access(struct domain *d, gfn_t gfn, xenmem_access_t *access)
+int p2m_get_mem_access(struct domain *d, gfn_t gfn, xenmem_access_t *access,
+ unsigned int altp2m_idx)
{
struct p2m_domain *p2m = p2m_get_hostp2m(d);

+#ifdef CONFIG_HVM
+ if ( !altp2m_active(d) )
+ {
+ if ( altp2m_idx )
+ return -EINVAL;
+ }
+ else
+ {
+ if ( altp2m_idx >= MAX_ALTP2M ||
+ d->arch.altp2m_eptp[altp2m_idx] == mfn_x(INVALID_MFN) )
+ return -EINVAL;
+
+ p2m = d->arch.altp2m_p2m[altp2m_idx];
+ }
+#else
+ ASSERT(!altp2m_idx);
+#endif
+
return _p2m_get_mem_access(p2m, gfn, access);
}

diff --git a/xen/common/mem_access.c b/xen/common/mem_access.c
index 1bf6824442..010e6f8dbf 100644
--- a/xen/common/mem_access.c
+++ b/xen/common/mem_access.c
@@ -99,7 +99,7 @@ int mem_access_memop(unsigned long cmd,
if ( (mao.pfn > domain_get_maximum_gpfn(d)) && mao.pfn != ~0ull )
break;

- rc = p2m_get_mem_access(d, _gfn(mao.pfn), &access);
+ rc = p2m_get_mem_access(d, _gfn(mao.pfn), &access, 0);
if ( rc != 0 )
break;

diff --git a/xen/include/public/hvm/hvm_op.h b/xen/include/public/hvm/hvm_op.h
index cf00cad164..5878a25fb3 100644
--- a/xen/include/public/hvm/hvm_op.h
+++ b/xen/include/public/hvm/hvm_op.h
@@ -242,17 +242,31 @@ struct xen_hvm_altp2m_view {
typedef struct xen_hvm_altp2m_view xen_hvm_altp2m_view_t;
DEFINE_XEN_GUEST_HANDLE(xen_hvm_altp2m_view_t);

+#if __XEN_INTERFACE_VERSION__ < 0x00040a00
struct xen_hvm_altp2m_set_mem_access {
/* view */
uint16_t view;
/* Memory type */
- uint16_t hvmmem_access; /* xenmem_access_t */
+ uint16_t access; /* xenmem_access_t */
uint32_t pad;
/* gfn */
uint64_t gfn;
};
typedef struct xen_hvm_altp2m_set_mem_access xen_hvm_altp2m_set_mem_access_t;
DEFINE_XEN_GUEST_HANDLE(xen_hvm_altp2m_set_mem_access_t);
+#endif /* __XEN_INTERFACE_VERSION__ < 0x00040a00 */
+
+struct xen_hvm_altp2m_mem_access {
+ /* view */
+ uint16_t view;
+ /* Memory type */
+ uint16_t access; /* xenmem_access_t */
+ uint32_t pad;
+ /* gfn */
+ uint64_t gfn;
+};
+typedef struct xen_hvm_altp2m_mem_access xen_hvm_altp2m_mem_access_t;
+DEFINE_XEN_GUEST_HANDLE(xen_hvm_altp2m_mem_access_t);

struct xen_hvm_altp2m_set_mem_access_multi {
/* view */
@@ -308,6 +322,8 @@ struct xen_hvm_altp2m_op {
#define HVMOP_altp2m_set_suppress_ve 10
/* Get the "Suppress #VE" bit of a page */
#define HVMOP_altp2m_get_suppress_ve 11
+/* Get the access of a page of memory from a certain view */
+#define HVMOP_altp2m_get_mem_access 12
domid_t domain;
uint16_t pad1;
uint32_t pad2;
@@ -315,7 +331,10 @@ struct xen_hvm_altp2m_op {
struct xen_hvm_altp2m_domain_state domain_state;
struct xen_hvm_altp2m_vcpu_enable_notify enable_notify;
struct xen_hvm_altp2m_view view;
+#if __XEN_INTERFACE_VERSION__ < 0x00040a00
struct xen_hvm_altp2m_set_mem_access set_mem_access;
+#endif /* __XEN_INTERFACE_VERSION__ < 0x00040a00 */
+ struct xen_hvm_altp2m_mem_access mem_access;
struct xen_hvm_altp2m_change_gfn change_gfn;
struct xen_hvm_altp2m_set_mem_access_multi set_mem_access_multi;
struct xen_hvm_altp2m_suppress_ve suppress_ve;
diff --git a/xen/include/public/xen-compat.h b/xen/include/public/xen-compat.h
index b67365340b..fa6ffb72e8 100644
--- a/xen/include/public/xen-compat.h
+++ b/xen/include/public/xen-compat.h
@@ -27,7 +27,7 @@
#ifndef __XEN_PUBLIC_XEN_COMPAT_H__
#define __XEN_PUBLIC_XEN_COMPAT_H__

-#define __XEN_LATEST_INTERFACE_VERSION__ 0x00040900
+#define __XEN_LATEST_INTERFACE_VERSION__ 0x00040a00

#if defined(__XEN__) || defined(__XEN_TOOLS__)
/* Xen is built with matching headers and implements the latest interface. */
diff --git a/xen/include/xen/mem_access.h b/xen/include/xen/mem_access.h
index 28cab673da..e4d24502e0 100644
--- a/xen/include/xen/mem_access.h
+++ b/xen/include/xen/mem_access.h
@@ -82,7 +82,8 @@ int p2m_get_suppress_ve(struct domain *d, gfn_t gfn, bool *suppress_ve,
* Get access type for a gfn.
* If gfn == INVALID_GFN, gets the default access type.
*/
-int p2m_get_mem_access(struct domain *d, gfn_t gfn, xenmem_access_t *access);
+int p2m_get_mem_access(struct domain *d, gfn_t gfn, xenmem_access_t *access,
+ unsigned int altp2m_idx);

#ifdef CONFIG_MEM_ACCESS
int mem_access_memop(unsigned long cmd,
--
generated by git-patchbot for /home/xen/git/xen.git#master

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