Having CONFIG_PV_SHIM conditionals in common code isn't really nice.
Utilize that we're no longer invoking hypercall handlers via indirect
calls through a table of function vectors. With the use of direct calls
from the macros defined by hypercall-defs.h, we can simply define
overriding macros for event channel and grant table ops handling. All
this requires is arrangement for careful double inclusion of
asm/hypercall.h out of xen/hypercall.h. Such double inclusion is
required because hypercall-defs.h expects certain definitions to be in
place, while the new handling (placed in pv/shim.h, which is now
included from asm/hypercall.h despite the apparent cyclic dependency)
requires prototypes from hypercall-defs.h to be available already.
Note that this makes it necessary to further constrain the stubbing of
pv_shim from common/sched/core.c, and allows removing the inclusion of
asm/guest.h there as well. Since this is actually part of the overall
goal, leverage the mechanism to also get rid of the similar construct in
xsm/flask/hooks.c, including xen/hypercall.h instead.
Note further that kind of as a side effect this fixes grant table
handling for 32-bit shim guests when GRANT_TABLE=y, as the non-stub
compat_grant_table_op() did not redirect to pv_shim_grant_table_op().
A downside of this is that now do_{event_channel,grant_table}_op() are
built in full again when PV_SHIM_EXCLUSIVE=y, despite all the code
actually being dead in that case.
Signed-off-by: Jan Beulich <jbeul...@suse.com>
---
RFC: Sadly I had to restore the two "#define pv_shim false", for Arm to
continue to build. Originally I was hoping to get rid of that
#ifdef-ary altogether. Would it be acceptable to put a single,
central #define in e.g. xen/sched.h or xen/hypercall.h?
--- a/xen/arch/x86/include/asm/hypercall.h
+++ b/xen/arch/x86/include/asm/hypercall.h
@@ -6,14 +6,23 @@
#error "asm/hypercall.h should not be included directly - include
xen/hypercall.h instead"
#endif
-#ifndef __ASM_X86_HYPERCALL_H__
-#define __ASM_X86_HYPERCALL_H__
-
#include <xen/types.h>
+#include <public/xen.h>
#include <public/physdev.h>
-#include <public/event_channel.h>
#include <public/arch-x86/xen-mca.h> /* for do_mca */
+
+#ifdef CONFIG_COMPAT
+#include <compat/arch-x86/xen.h>
+#include <compat/physdev.h>
+#include <compat/platform.h>
+#endif
+
+#if !defined(__ASM_X86_HYPERCALL_H__) && \
+ (!defined(CONFIG_PV_SHIM) || defined(hypercall_args_pv64))
+#define __ASM_X86_HYPERCALL_H__
+
#include <asm/paging.h>
+#include <asm/pv/shim.h>
#define __HYPERVISOR_paging_domctl_cont __HYPERVISOR_arch_1
@@ -33,10 +42,6 @@ void pv_ring3_init_hypercall_page(void *
#ifdef CONFIG_COMPAT
-#include <compat/arch-x86/xen.h>
-#include <compat/physdev.h>
-#include <compat/platform.h>
-
extern int
compat_common_vcpu_op(
int cmd, struct vcpu *v, XEN_GUEST_HANDLE_PARAM(void) arg);
--- a/xen/arch/x86/include/asm/pv/shim.h
+++ b/xen/arch/x86/include/asm/pv/shim.h
@@ -49,6 +49,22 @@ const struct platform_bad_page *pv_shim_
typeof(do_event_channel_op) pv_shim_event_channel_op;
typeof(do_grant_table_op) pv_shim_grant_table_op;
+#ifdef CONFIG_PV_SHIM_EXCLUSIVE
+#define REVECTOR(pfx, op, args...) pv_shim_ ## op(args)
+#else
+#define REVECTOR(pfx, op, args...) ({ \
+ likely(!pv_shim) \
+ ? pfx ## _ ## op(args) \
+ : pv_shim_ ## op(args); \
+})
+#endif
+
+#define do_event_channel_op(args...) REVECTOR(do, event_channel_op, args)
+#define do_grant_table_op(args...) REVECTOR(do, grant_table_op, args)
+#ifdef CONFIG_COMPAT
+#define compat_grant_table_op(args...) REVECTOR(compat, grant_table_op, args)
+#endif
+
#else
static inline void pv_shim_setup_dom(struct domain *d, l4_pgentry_t *l4start,
--- a/xen/arch/x86/pv/shim.c
+++ b/xen/arch/x86/pv/shim.c
@@ -822,9 +822,9 @@ long pv_shim_grant_table_op(unsigned int
return rc;
}
-#ifndef CONFIG_GRANT_TABLE
+#if !defined(CONFIG_GRANT_TABLE) && !defined(CONFIG_PV_SHIM_EXCLUSIVE)
/* Thin wrapper(s) needed. */
-long do_grant_table_op(
+long (do_grant_table_op)(
unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) uop, unsigned int count)
{
if ( !pv_shim )
@@ -834,7 +834,7 @@ long do_grant_table_op(
}
#ifdef CONFIG_PV32
-int compat_grant_table_op(
+int (compat_grant_table_op)(
unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) uop, unsigned int count)
{
if ( !pv_shim )
--- a/xen/common/compat/grant_table.c
+++ b/xen/common/compat/grant_table.c
@@ -56,7 +56,7 @@ CHECK_gnttab_swap_grant_ref;
CHECK_gnttab_cache_flush;
#undef xen_gnttab_cache_flush
-int compat_grant_table_op(
+int (compat_grant_table_op)(
unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) cmp_uop, unsigned int count)
{
int rc = 0;
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -32,10 +32,6 @@
#include <public/event_channel.h>
#include <xsm/xsm.h>
-#ifdef CONFIG_PV_SHIM
-#include <asm/guest.h>
-#endif
-
#define ERROR_EXIT(_errno) \
do { \
gdprintk(XENLOG_WARNING, \
@@ -1222,15 +1218,10 @@ static int evtchn_set_priority(const str
return ret;
}
-long do_event_channel_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
+long (do_event_channel_op)(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
{
int rc;
-#ifdef CONFIG_PV_SHIM
- if ( unlikely(pv_shim) )
- return pv_shim_event_channel_op(cmd, arg);
-#endif
-
switch ( cmd )
{
case EVTCHNOP_alloc_unbound: {
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -45,10 +45,6 @@
#include <asm/flushtlb.h>
#include <asm/guest_atomics.h>
-#ifdef CONFIG_PV_SHIM
-#include <asm/guest.h>
-#endif
-
/* Per-domain grant information. */
struct grant_table {
/*
@@ -3563,17 +3559,12 @@ gnttab_cache_flush(XEN_GUEST_HANDLE_PARA
return 0;
}
-long do_grant_table_op(
+long (do_grant_table_op)(
unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) uop, unsigned int count)
{
long rc;
unsigned int opaque_in = cmd & GNTTABOP_ARG_MASK, opaque_out = 0;
-#ifdef CONFIG_PV_SHIM
- if ( unlikely(pv_shim) )
- return pv_shim_grant_table_op(cmd, uop, count);
-#endif
-
if ( (int)count < 0 )
return -EINVAL;
--- a/xen/common/sched/core.c
+++ b/xen/common/sched/core.c
@@ -40,9 +40,7 @@
#include "private.h"
-#ifdef CONFIG_XEN_GUEST
-#include <asm/guest.h>
-#else
+#ifndef CONFIG_X86
#define pv_shim false
#endif
--- a/xen/include/xen/hypercall.h
+++ b/xen/include/xen/hypercall.h
@@ -24,6 +24,9 @@
/* Needs to be after asm/hypercall.h. */
#include <xen/hypercall-defs.h>
+/* Include a 2nd time, for x86'es PV shim. */
+#include <asm/hypercall.h>
+
extern long
arch_do_domctl(
struct xen_domctl *domctl, struct domain *d,
--- a/xen/xsm/flask/hooks.c
+++ b/xen/xsm/flask/hooks.c
@@ -19,6 +19,7 @@
#include <xen/cpumask.h>
#include <xen/errno.h>
#include <xen/guest_access.h>
+#include <xen/hypercall.h>
#include <xen/xenoprof.h>
#include <xen/iommu.h>
#ifdef CONFIG_HAS_PCI_MSI
@@ -38,9 +39,7 @@
#include <conditional.h>
#include "private.h"
-#ifdef CONFIG_X86
-#include <asm/pv/shim.h>
-#else
+#ifndef CONFIG_X86
#define pv_shim false
#endif
