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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] x86/pv-shim: Don't modify the hypercall table
commit e7db635f4428cabbb72ba33a6ec6e1465f2169cb
Author: Juergen Gross <jgross@xxxxxxxx>
AuthorDate: Mon Nov 1 16:20:09 2021 +0100
Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Wed Feb 23 15:33:42 2022 +0000
x86/pv-shim: Don't modify the hypercall table
When running as pv-shim the hypercall is modified today in order to
replace the functions for __HYPERVISOR_event_channel_op and
__HYPERVISOR_grant_table_op hypercalls.
Change this to call the related functions from the normal handlers
instead when running as shim. The performance implications are not
really relevant, as a normal production hypervisor will not be
configured to support shim mode, so the related calls will be dropped
due to optimisation of the compiler.
Note that for the CONFIG_PV_SHIM_EXCLUSIVE case there is a dummy
wrapper do_grant_table_op() needed, as in this case grant_table.c
isn't being built.
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Split out of series. To compile in isolation, the compat_platform_op()
prototype needs correcting, and header files need rearranging to avoid the
compat_platform_op_t/multicall_entry_compat_t guest handles being declared
multiple times.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
xen/arch/x86/include/asm/hypercall.h | 4 ++-
xen/arch/x86/include/asm/pv/shim.h | 3 ++
xen/arch/x86/pv/hypercall.c | 2 +-
xen/arch/x86/pv/shim.c | 54 ++++++++++++++++----------------
xen/arch/x86/x86_64/platform_hypercall.c | 2 +-
xen/common/compat/multicall.c | 3 +-
xen/common/event_channel.c | 9 ++++++
xen/common/grant_table.c | 9 ++++++
8 files changed, 54 insertions(+), 32 deletions(-)
diff --git a/xen/arch/x86/include/asm/hypercall.h
b/xen/arch/x86/include/asm/hypercall.h
index 5d394d4923..f004824f16 100644
--- a/xen/arch/x86/include/asm/hypercall.h
+++ b/xen/arch/x86/include/asm/hypercall.h
@@ -145,6 +145,7 @@ do_set_segment_base(
#include <compat/arch-x86/xen.h>
#include <compat/physdev.h>
+#include <compat/platform.h>
extern int
compat_physdev_op(
@@ -161,8 +162,9 @@ extern int compat_mmuext_op(
XEN_GUEST_HANDLE_PARAM(uint) pdone,
unsigned int foreigndom);
+DEFINE_XEN_GUEST_HANDLE(compat_platform_op_t);
extern int compat_platform_op(
- XEN_GUEST_HANDLE_PARAM(void) u_xenpf_op);
+ XEN_GUEST_HANDLE_PARAM(compat_platform_op_t) u_xenpf_op);
extern long compat_callback_op(
int cmd, XEN_GUEST_HANDLE(void) arg);
diff --git a/xen/arch/x86/include/asm/pv/shim.h
b/xen/arch/x86/include/asm/pv/shim.h
index 8a91f4f9df..6415f8068e 100644
--- a/xen/arch/x86/include/asm/pv/shim.h
+++ b/xen/arch/x86/include/asm/pv/shim.h
@@ -19,6 +19,7 @@
#ifndef __X86_PV_SHIM_H__
#define __X86_PV_SHIM_H__
+#include <xen/hypercall.h>
#include <xen/types.h>
#if defined(CONFIG_PV_SHIM_EXCLUSIVE)
@@ -45,6 +46,8 @@ domid_t get_initial_domain_id(void);
uint64_t pv_shim_mem(uint64_t avail);
void pv_shim_fixup_e820(struct e820map *e820);
const struct platform_bad_page *pv_shim_reserved_pages(unsigned int *size);
+typeof(do_event_channel_op) pv_shim_event_channel_op;
+typeof(do_grant_table_op) pv_shim_grant_table_op;
#else
diff --git a/xen/arch/x86/pv/hypercall.c b/xen/arch/x86/pv/hypercall.c
index ecdd58deea..50cd219c18 100644
--- a/xen/arch/x86/pv/hypercall.c
+++ b/xen/arch/x86/pv/hypercall.c
@@ -64,7 +64,7 @@ const pv_hypercall_table_t pv_hypercall_table[] = {
COMPAT_CALL(xen_version),
HYPERCALL(console_io),
COMPAT_CALL(physdev_op_compat),
-#ifdef CONFIG_GRANT_TABLE
+#if defined(CONFIG_GRANT_TABLE) || defined(CONFIG_PV_SHIM)
COMPAT_CALL(grant_table_op),
#endif
HYPERCALL(vm_assist),
diff --git a/xen/arch/x86/pv/shim.c b/xen/arch/x86/pv/shim.c
index d9704121a7..7e891fe2f7 100644
--- a/xen/arch/x86/pv/shim.c
+++ b/xen/arch/x86/pv/shim.c
@@ -56,11 +56,6 @@ static DEFINE_SPINLOCK(balloon_lock);
static struct platform_bad_page __initdata reserved_pages[2];
-static long pv_shim_event_channel_op(int cmd, XEN_GUEST_HANDLE_PARAM(void)
arg);
-static long pv_shim_grant_table_op(unsigned int cmd,
- XEN_GUEST_HANDLE_PARAM(void) uop,
- unsigned int count);
-
/*
* By default give the shim 1MB of free memory slack. Some users may wish to
* tune this constants for better memory utilization. This can be achieved
@@ -203,7 +198,6 @@ void __init pv_shim_setup_dom(struct domain *d,
l4_pgentry_t *l4start,
start_info_t *si)
{
bool compat = is_pv_32bit_domain(d);
- pv_hypercall_table_t *rw_pv_hypercall_table;
uint64_t param = 0;
long rc;
@@ -249,23 +243,6 @@ void __init pv_shim_setup_dom(struct domain *d,
l4_pgentry_t *l4start,
consoled_set_ring_addr(page);
}
- /*
- * Locate pv_hypercall_table[] (usually .rodata) in the directmap (which
- * is writeable) and insert some shim-specific hypercall handlers.
- */
- rw_pv_hypercall_table = __va(__pa(pv_hypercall_table));
- rw_pv_hypercall_table[__HYPERVISOR_event_channel_op].native =
- (hypercall_fn_t *)pv_shim_event_channel_op;
- rw_pv_hypercall_table[__HYPERVISOR_grant_table_op].native =
- (hypercall_fn_t *)pv_shim_grant_table_op;
-
-#ifdef CONFIG_PV32
- rw_pv_hypercall_table[__HYPERVISOR_event_channel_op].compat =
- (hypercall_fn_t *)pv_shim_event_channel_op;
- rw_pv_hypercall_table[__HYPERVISOR_grant_table_op].compat =
- (hypercall_fn_t *)pv_shim_grant_table_op;
-#endif
-
guest = d;
/*
@@ -435,7 +412,7 @@ int pv_shim_shutdown(uint8_t reason)
return 0;
}
-static long pv_shim_event_channel_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
+long pv_shim_event_channel_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
{
struct domain *d = current->domain;
struct evtchn_close close;
@@ -683,9 +660,9 @@ void pv_shim_inject_evtchn(unsigned int port)
# define compat_handle_okay guest_handle_okay
#endif
-static long pv_shim_grant_table_op(unsigned int cmd,
- XEN_GUEST_HANDLE_PARAM(void) uop,
- unsigned int count)
+long pv_shim_grant_table_op(unsigned int cmd,
+ XEN_GUEST_HANDLE_PARAM(void) uop,
+ unsigned int count)
{
struct domain *d = current->domain;
long rc = 0;
@@ -845,6 +822,29 @@ static long pv_shim_grant_table_op(unsigned int cmd,
return rc;
}
+#ifndef CONFIG_GRANT_TABLE
+/* Thin wrapper(s) needed. */
+long do_grant_table_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) uop,
+ unsigned int count)
+{
+ if ( !pv_shim )
+ return -ENOSYS;
+
+ return pv_shim_grant_table_op(cmd, uop, count);
+}
+
+#ifdef CONFIG_PV32
+int compat_grant_table_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) uop,
+ unsigned int count)
+{
+ if ( !pv_shim )
+ return -ENOSYS;
+
+ return pv_shim_grant_table_op(cmd, uop, count);
+}
+#endif
+#endif
+
long pv_shim_cpu_up(void *data)
{
struct vcpu *v = data;
diff --git a/xen/arch/x86/x86_64/platform_hypercall.c
b/xen/arch/x86/x86_64/platform_hypercall.c
index fbba893a47..966fd27b5f 100644
--- a/xen/arch/x86/x86_64/platform_hypercall.c
+++ b/xen/arch/x86/x86_64/platform_hypercall.c
@@ -6,8 +6,8 @@ EMIT_FILE;
#include <xen/lib.h>
#include <compat/platform.h>
+#include <xen/hypercall.h>
-DEFINE_XEN_GUEST_HANDLE(compat_platform_op_t);
#define xen_platform_op compat_platform_op
#define xen_platform_op_t compat_platform_op_t
#define do_platform_op(x) compat_platform_op(_##x)
diff --git a/xen/common/compat/multicall.c b/xen/common/compat/multicall.c
index a0e9918f48..b17739d218 100644
--- a/xen/common/compat/multicall.c
+++ b/xen/common/compat/multicall.c
@@ -5,7 +5,7 @@
EMIT_FILE;
#include <xen/types.h>
-#include <xen/multicall.h>
+#include <xen/hypercall.h>
#include <xen/trace.h>
#define COMPAT
@@ -19,7 +19,6 @@ static inline void xlat_multicall_entry(struct mc_state *mcs)
mcs->compat_call.args[i] = mcs->call.args[i];
}
-DEFINE_XEN_GUEST_HANDLE(multicall_entry_compat_t);
#define multicall_entry compat_multicall_entry
#define multicall_entry_t multicall_entry_compat_t
#define do_multicall_call compat_multicall_call
diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index da88ad141a..c9912122d1 100644
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -31,6 +31,10 @@
#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, \
@@ -1189,6 +1193,11 @@ 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: {
diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index 3d92fee592..925ed7d6be 100644
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -44,6 +44,10 @@
#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 {
/*
@@ -3561,6 +3565,11 @@ do_grant_table_op(
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;
--
generated by git-patchbot for /home/xen/git/xen.git#staging
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