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xen: generate hypercall interface related code

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Instead of repeating similar data multiple times use a single source
file and a generator script for producing prototypes and call sequences
of the hypercalls.

As the script already knows the number of parameters used add generating
a macro for populating an array with the number of parameters per
hypercall.

The priorities for the specific hypercalls are based on two benchamrks
performed in guests (PV and PVH):

- make -j 4 of the Xen hypervisor (resulting in cpu load with lots of
  processes created)
- scp of a large file to the guest (network load)

With a small additional debug patch applied the number of the
different hypercalls in the guest and in dom0 (for looking at backend
activity related hypercalls) were counted while the benchmark in domU
was running:

PV-hypercall    PV-guest build   PV-guest scp    dom0 build     dom0 scp
mmu_update           186175729           2865         20936        33725
stack_switch           1273311          62381        108589       270764
multicall              2182803             50           302          524
update_va_mapping       571868             10            60           80
xen_version              73061            850           859         5432
grant_table_op               0              0         35557       139110
iret                  75673006         484132        268157       757958
vcpu_op                 453037          71199        138224       334988
set_segment_base       1650249          62387        108645       270823
mmuext_op             11225681            188          7239         3426
sched_op                280153         134645         70729       137943
event_channel_op        192327          66204         71409       214191
physdev_op                   0              0          7721         4315
(the dom0 values are for the guest running the build or scp test, so
dom0 acting as backend)

HVM-hypercall   PVH-guest build    PVH-guest scp
vcpu_op                  277684             2324
event_channel_op         350233            57383
(the related dom0 counter values are in the same range as with the test
running in the PV guest)

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
This commit is contained in:
Juergen Gross authored and Jan Beulich committed 2022-07-11 12:06:19 +02:00
1 parent e1664942b2
commit eca1f00d02
4 files changed
+613
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.gitignore
+1
View File
@@ -327,6 +327,7 @@ xen/include/public/public
xen/include/xen/*.new
xen/include/xen/acm_policy.h
xen/include/xen/compile.h
xen/include/xen/hypercall-defs.h
xen/include/xen/lib/x86/cpuid-autogen.h
xen/source
xen/test/livepatch/config.h
xen/include/Makefile
+13
View File
@@ -104,6 +104,18 @@ cmd_xlat_h = \
$(obj)/compat/xlat.h: $(addprefix $(obj)/compat/.xlat/,$(xlat-y)) FORCE
$(call if_changed,xlat_h)
quiet_cmd_genhyp = GEN $@
define cmd_genhyp
awk -f $(srctree)/scripts/gen_hypercall.awk <$< >$@
endef
all: $(obj)/xen/hypercall-defs.h
$(obj)/xen/hypercall-defs.h: $(obj)/hypercall-defs.i $(srctree)/scripts/gen_hypercall.awk FORCE
$(call if_changed,genhyp)
targets += xen/hypercall-defs.h
ifeq ($(XEN_TARGET_ARCH),$(XEN_COMPILE_ARCH))
all: $(obj)/headers.chk $(obj)/headers99.chk $(obj)/headers++.chk
@@ -213,3 +225,4 @@ all: lib-x86-all
endif
clean-files := compat config generated headers*.chk xen/lib/x86/cpuid-autogen.h
clean-files += xen/hypercall-defs.h hypercall-defs.i
xen/include/hypercall-defs.c
+285
View File
@@ -0,0 +1,285 @@
/*
* Hypercall interface description:
* Used by scripts/gen_hypercall.awk to generate hypercall prototypes and call
* sequences.
*
* Syntax is like a prototype, but without return type and without the ";" at
* the end. Pointer types will be automatically converted to use the
* XEN_GUEST_HANDLE_PARAM() macro. Handlers with no parameters just use a
* definition like "fn()".
* Hypercall/function names are without the leading "__HYPERVISOR_"/"do_"
* strings.
*
* The return type of a class of prototypes using the same prefix is set via:
* rettype: <prefix> <type>
* Default return type is "long". A return type for a prefix can be set only
* once and it needs to be set before that prefix is being used via the
* "prefix:" directive.
*
* The prefix of the prototypes is set via a line:
* prefix: <prefix> ...
* Multiple prefixes are possible (restriction see below). Prefixes are without
* a trailing "_". The current prefix settings are active until a new "prefix:"
* line.
*
* Caller macros are suffixed with a selectable name via lines like:
* caller: <suffix>
* When a caller suffix is active, there is only one active prefix allowed.
*
* With a "defhandle:" line it is possible to add a DEFINE_XEN_GUEST_HANDLE()
* to the generated header:
* defhandle: <handle-type> [<type>]
* Without specifying <type> only a DEFINE_XEN_GUEST_HANDLE(<handle-type>)
* will be generated, otherwise it will be a
* __DEFINE_XEN_GUEST_HANDLE(<handle-type>, <type>) being generated. Note that
* the latter will include the related "const" handle "const_<handle-type>".
*
* In order to support using coding style compliant pointers in the
* prototypes it is possible to add translation entries to generate the correct
* handle types:
* handle: <handle-type> <type>
* This will result in the prototype translation from "<type> *" to
* "XEN_GUEST_HANDLE_PARAM(<handle-type>)".
*
* The hypercall handler calling code will be generated from a final table in
* the source file, which is started via the line:
* table: <caller> <caller> ...
* with the <caller>s specifying the designated caller macro of each column of
* the table. Any column of a <caller> not having been set via a "caller:"
* line will be ignored.
* The first column of the table contains the hypercall/prototype, each
* <caller> column contains the prefix for the function to use for that caller.
* A function prefix can be annotated with a priority by adding ":<prio>" to it
* ("1" being the highest priority, higher numbers mean lower priority, no
* priority specified is the lowest priority). The generated code will try to
* achieve better performance for calling high priority handlers.
* A column not being supported by a <caller> is marked with "-". Lines with all
* entries being "-" after removal of inactive <caller> columns are ignored.
*
* This file is being preprocessed using $(CPP), so #ifdef CONFIG_* conditionals
* are possible.
*/
#ifdef CONFIG_HVM
#define PREFIX_hvm hvm
#else
#define PREFIX_hvm
#endif
#ifdef CONFIG_COMPAT
#define PREFIX_compat compat
rettype: compat int
#else
#define PREFIX_compat
#endif
#ifdef CONFIG_ARM
#define PREFIX_dep dep
#define PREFIX_do_arm do_arm
rettype: do_arm int
#else
#define PREFIX_dep
#define PREFIX_do_arm
#endif
handle: uint unsigned int
handle: const_void const void
handle: const_char const char
#ifdef CONFIG_COMPAT
defhandle: multicall_entry_compat_t
#ifndef CONFIG_PV_SHIM_EXCLUSIVE
defhandle: compat_platform_op_t
#endif
#endif
#ifdef CONFIG_PV32
defhandle: trap_info_compat_t
defhandle: physdev_op_compat_t
#endif
prefix: do PREFIX_hvm PREFIX_compat PREFIX_do_arm
physdev_op(int cmd, void *arg)
prefix: do PREFIX_hvm PREFIX_compat
#if defined(CONFIG_GRANT_TABLE) || defined(CONFIG_PV_SHIM)
grant_table_op(unsigned int cmd, void *uop, unsigned int count)
#endif
prefix: do PREFIX_hvm
memory_op(unsigned long cmd, void *arg)
prefix: do PREFIX_compat
xen_version(int cmd, void *arg)
vcpu_op(int cmd, unsigned int vcpuid, void *arg)
sched_op(int cmd, void *arg)
xsm_op(void *op)
callback_op(int cmd, const void *arg)
#ifdef CONFIG_ARGO
argo_op(unsigned int cmd, void *arg1, void *arg2, unsigned long arg3, unsigned long arg4)
#endif
#ifdef CONFIG_KEXEC
kexec_op(unsigned int op, void *uarg)
#endif
#ifdef CONFIG_PV
iret()
nmi_op(unsigned int cmd, void *arg)
#ifdef CONFIG_XENOPROF
xenoprof_op(int op, void *arg)
#endif
#endif /* CONFIG_PV */
#ifdef CONFIG_COMPAT
prefix: compat
set_timer_op(uint32_t lo, int32_t hi)
multicall(multicall_entry_compat_t *call_list, uint32_t nr_calls)
memory_op(unsigned int cmd, void *arg)
#ifdef CONFIG_IOREQ_SERVER
dm_op(domid_t domid, unsigned int nr_bufs, void *bufs)
#endif
mmuext_op(void *arg, unsigned int count, uint *pdone, unsigned int foreigndom)
#ifdef CONFIG_PV32
set_trap_table(trap_info_compat_t *traps)
set_gdt(unsigned int *frame_list, unsigned int entries)
set_callbacks(unsigned long event_selector, unsigned long event_address, unsigned long failsafe_selector, unsigned long failsafe_address)
update_descriptor(uint32_t pa_lo, uint32_t pa_hi, uint32_t desc_lo, uint32_t desc_hi)
update_va_mapping(unsigned int va, uint32_t lo, uint32_t hi, unsigned int flags)
physdev_op_compat(physdev_op_compat_t *uop)
update_va_mapping_otherdomain(unsigned int va, uint32_t lo, uint32_t hi, unsigned int flags, domid_t domid)
#endif
#ifndef CONFIG_PV_SHIM_EXCLUSIVE
platform_op(compat_platform_op_t *u_xenpf_op)
#endif
#endif /* CONFIG_COMPAT */
#if defined(CONFIG_PV) || defined(CONFIG_ARM)
prefix: do PREFIX_dep
event_channel_op_compat(evtchn_op_t *uop)
physdev_op_compat(physdev_op_t *uop)
/* Legacy hypercall (as of 0x00030101). */
sched_op_compat(int cmd, unsigned long arg)
#endif
prefix: do
set_timer_op(s_time_t timeout)
console_io(unsigned int cmd, unsigned int count, char *buffer)
vm_assist(unsigned int cmd, unsigned int type)
event_channel_op(int cmd, void *arg)
mmuext_op(mmuext_op_t *uops, unsigned int count, unsigned int *pdone, unsigned int foreigndom)
multicall(multicall_entry_t *call_list, unsigned int nr_calls)
#ifdef CONFIG_PV
mmu_update(mmu_update_t *ureqs, unsigned int count, unsigned int *pdone, unsigned int foreigndom)
stack_switch(unsigned long ss, unsigned long esp)
fpu_taskswitch(int set)
set_debugreg(int reg, unsigned long value)
get_debugreg(int reg)
set_segment_base(unsigned int which, unsigned long base)
mca(xen_mc_t *u_xen_mc)
set_trap_table(const_trap_info_t *traps)
set_gdt(xen_ulong_t *frame_list, unsigned int entries)
set_callbacks(unsigned long event_address, unsigned long failsafe_address, unsigned long syscall_address)
update_descriptor(uint64_t gaddr, seg_desc_t desc)
update_va_mapping(unsigned long va, uint64_t val64, unsigned long flags)
update_va_mapping_otherdomain(unsigned long va, uint64_t val64, unsigned long flags, domid_t domid)
#endif
#ifdef CONFIG_IOREQ_SERVER
dm_op(domid_t domid, unsigned int nr_bufs, xen_dm_op_buf_t *bufs)
#endif
#ifndef CONFIG_PV_SHIM_EXCLUSIVE
sysctl(xen_sysctl_t *u_sysctl)
domctl(xen_domctl_t *u_domctl)
paging_domctl_cont(xen_domctl_t *u_domctl)
platform_op(xen_platform_op_t *u_xenpf_op)
#endif
#ifdef CONFIG_HVM
hvm_op(unsigned long op, void *arg)
#endif
#ifdef CONFIG_HYPFS
hypfs_op(unsigned int cmd, const char *arg1, unsigned long arg2, void *arg3, unsigned long arg4)
#endif
#ifdef CONFIG_X86
xenpmu_op(unsigned int op, xen_pmu_params_t *arg)
#endif
#ifdef CONFIG_PV
caller: pv64
#ifdef CONFIG_PV32
caller: pv32
#endif
#endif
#if defined(CONFIG_HVM) && defined(CONFIG_X86)
caller: hvm64
#ifdef CONFIG_COMPAT
caller: hvm32
#endif
#endif
#ifdef CONFIG_ARM
caller: arm
#endif
table: pv32 pv64 hvm32 hvm64 arm
set_trap_table compat do - - -
mmu_update do:1 do:1 - - -
set_gdt compat do - - -
stack_switch do:2 do:2 - - -
set_callbacks compat do - - -
fpu_taskswitch do do - - -
sched_op_compat do do - - dep
#ifndef CONFIG_PV_SHIM_EXCLUSIVE
platform_op compat do compat do do
#endif
set_debugreg do do - - -
get_debugreg do do - - -
update_descriptor compat do - - -
memory_op compat do hvm hvm do
multicall compat:2 do:2 compat do do
update_va_mapping compat do - - -
set_timer_op compat do compat do -
event_channel_op_compat do do - - dep
xen_version compat do compat do do
console_io do do do do do
physdev_op_compat compat do - - dep
#if defined(CONFIG_GRANT_TABLE) || defined(CONFIG_PV_SHIM)
grant_table_op compat do hvm hvm do
#endif
vm_assist do do do do do
update_va_mapping_otherdomain compat do - - -
iret compat:1 do:1 - - -
vcpu_op compat do compat:1 do:1 do
set_segment_base do:2 do:2 - - -
#ifdef CONFIG_PV
mmuext_op compat:2 do:2 compat do -
#endif
xsm_op compat do compat do do
nmi_op compat do - - -
sched_op compat do compat do do
callback_op compat do - - -
#ifdef CONFIG_XENOPROF
xenoprof_op compat do - - -
#endif
event_channel_op do do do:1 do:1 do:1
physdev_op compat do hvm hvm do_arm
#ifdef CONFIG_HVM
hvm_op do do do do do
#endif
#ifndef CONFIG_PV_SHIM_EXCLUSIVE
sysctl do do do do do
domctl do do do do do
#endif
#ifdef CONFIG_KEXEC
kexec_op compat do - - -
#endif
tmem_op - - - - -
#ifdef CONFIG_ARGO
argo_op compat do compat do do
#endif
xenpmu_op do do do do -
#ifdef CONFIG_IOREQ_SERVER
dm_op compat do compat do do
#endif
#ifdef CONFIG_HYPFS
hypfs_op do do do do do
#endif
mca do do - - -
#ifndef CONFIG_PV_SHIM_EXCLUSIVE
paging_domctl_cont do do do do -
#endif
xen/scripts/gen_hypercall.awk
+314
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@@ -0,0 +1,314 @@
# awk script to generate hypercall handler prototypes and a macro for doing
# the calls of the handlers inside a switch() statement.
BEGIN {
printf("/* Generated file, do not edit! */\n\n");
e = 0;
n = 0;
p = 0;
nc = 0;
}
# Issue error to stderr
function do_err(msg) {
print "Error: "msg": "$0 >"/dev/stderr";
exit 1;
}
# Generate handler call
function do_call(f, p, i) {
printf(" ret = %s_%s(", pre[f, p], fn[f]);
for (i = 1; i <= n_args[f]; i++) {
if (i > 1)
printf(", ");
if (ptr[f, i])
printf("(XEN_GUEST_HANDLE_PARAM(%s)){ _p(a%d) }", typ[f, i], i);
else
printf("(%s)(a%d)", typ[f, i], i);
}
printf("); \\\n");
}
# Generate case statement for call
function do_case(f, p) {
printf(" case __HYPERVISOR_%s: \\\n", fn[f]);
do_call(f, p);
printf(" break; \\\n");
}
# Generate switch statement for calling handlers
function do_switch(ca, p, i) {
printf(" switch ( num ) \\\n");
printf(" { \\\n");
for (i = 1; i <= nc; i++)
if (call[i] == ca && call_prio[i] == p)
do_case(call_fn[i], call_p[i]);
printf(" default: \\\n");
printf(" ret = -ENOSYS; \\\n");
printf(" break; \\\n");
printf(" } \\\n");
}
function rest_of_line(par, i, val) {
val = $(par);
for (i = par + 1; i <= NF; i++)
val = val " " $(i);
return val;
}
# Handle comments (multi- and single line)
$1 == "/*" {
comment = 1;
}
comment == 1 {
if ($(NF) == "*/") comment = 0;
next;
}
# Skip preprocessing artefacts
$1 == "extern" {
next;
}
/^#/ {
next;
}
# Drop empty lines
NF == 0 {
next;
}
# Handle "handle:" line
$1 == "handle:" {
if (NF < 3)
do_err("\"handle:\" requires at least two parameters");
val = rest_of_line(3);
xlate[val] = $2;
next;
}
# Handle "defhandle:" line
$1 == "defhandle:" {
if (NF < 2)
do_err("\"defhandle:\" requires at least one parameter");
e++;
if (NF == 2) {
emit[e] = sprintf("DEFINE_XEN_GUEST_HANDLE(%s);", $2);
} else {
val = rest_of_line(3);
emit[e] = sprintf("__DEFINE_XEN_GUEST_HANDLE(%s, %s);", $2, val);
xlate[val] = $2;
}
next;
}
# Handle "rettype:" line
$1 == "rettype:" {
if (NF < 3)
do_err("\"rettype:\" requires at least two parameters");
if ($2 in rettype)
do_err("rettype can be set only once for each prefix");
rettype[$2] = rest_of_line(3);
next;
}
# Handle "caller:" line
$1 == "caller:" {
caller[$2] = 1;
next;
}
# Handle "prefix:" line
$1 == "prefix:" {
p = NF - 1;
for (i = 2; i <= NF; i++) {
prefix[i - 1] = $(i);
if (!(prefix[i - 1] in rettype))
rettype[prefix[i - 1]] = "long";
}
next;
}
# Handle "table:" line
$1 == "table:" {
table = 1;
for (i = 2; i <= NF; i++)
col[i - 1] = $(i);
n_cols = NF - 1;
next;
}
# Handle table definition line
table == 1 {
if (NF != n_cols + 1)
do_err("Table definition line has wrong number of fields");
for (c = 1; c <= n_cols; c++) {
if (caller[col[c]] != 1)
continue;
if ($(c + 1) == "-")
continue;
pref = $(c + 1);
idx = index(pref, ":");
if (idx == 0)
prio = 100;
else {
prio = substr(pref, idx + 1) + 0;
pref = substr(pref, 1, idx - 1);
if (prio >= 100 || prio < 1)
do_err("Priority must be in the range 1..99");
}
fnd = 0;
for (i = 1; i <= n; i++) {
if (fn[i] != $1)
continue;
for (j = 1; j <= n_pre[i]; j++) {
if (pre[i, j] == pref) {
prios[col[c], prio]++;
if (prios[col[c], prio] == 1) {
n_prios[col[c]]++;
prio_list[col[c], n_prios[col[c]]] = prio;
prio_mask[col[c], prio] = "(1ULL << __HYPERVISOR_"$1")";
} else
prio_mask[col[c], prio] = prio_mask[col[c], prio] " | (1ULL << __HYPERVISOR_"$1")";
nc++;
call[nc] = col[c];
call_fn[nc] = i;
call_p[nc] = j;
call_prio[nc] = prio;
fnd = 1;
}
}
}
if (fnd == 0)
do_err("No prototype for prefix/hypercall combination");
}
next;
}
# Prototype line
{
bro = index($0, "(");
brc = index($0, ")");
if (bro < 2 || brc < bro)
do_err("No valid prototype line");
n++;
fn[n] = substr($0, 1, bro - 1);
n_pre[n] = p;
for (i = 1; i <= p; i++)
pre[n, i] = prefix[i];
args = substr($0, bro + 1, brc - bro - 1);
n_args[n] = split(args, a, ",");
if (n_args[n] > 5)
do_err("Too many parameters");
for (i = 1; i <= n_args[n]; i++) {
sub("^ *", "", a[i]); # Remove leading white space
sub(" +", " ", a[i]); # Replace multiple spaces with single ones
sub(" *$", "", a[i]); # Remove trailing white space
ptr[n, i] = index(a[i], "*"); # Is it a pointer type?
sub("[*]", "", a[i]); # Remove "*"
if (index(a[i], " ") == 0)
do_err("Parameter with no type or no name");
typ[n, i] = a[i];
sub(" [^ ]+$", "", typ[n, i]); # Remove parameter name
if (ptr[n, i] && (typ[n, i] in xlate))
typ[n, i] = xlate[typ[n, i]];
arg[n, i] = a[i];
sub("^([^ ]+ )+", "", arg[n, i]); # Remove parameter type
}
}
# Generate the output
END {
# Verbatim generated lines
for (i = 1; i <= e; i++)
printf("%s\n", emit[i]);
printf("\n");
# Generate prototypes
for (i = 1; i <= n; i++) {
for (p = 1; p <= n_pre[i]; p++) {
printf("%s cf_check %s_%s(", rettype[pre[i, p]], pre[i, p], fn[i]);
if (n_args[i] == 0)
printf("void");
else
for (j = 1; j <= n_args[i]; j++) {
if (j > 1)
printf(", ");
if (ptr[i, j])
printf("XEN_GUEST_HANDLE_PARAM(%s)", typ[i, j]);
else
printf("%s", typ[i, j]);
printf(" %s", arg[i, j]);
}
printf(");\n");
}
}
# Generate call sequences and args array contents
for (ca in caller) {
if (caller[ca] != 1)
continue;
need_mask = 0;
for (pl = 1; pl <= n_prios[ca]; pl++) {
for (pll = pl; pll > 1; pll--) {
if (prio_list[ca, pl] > p_list[pll - 1])
break;
else
p_list[pll] = p_list[pll - 1];
}
p_list[pll] = prio_list[ca, pl];
# If any prio but the default one has more than 1 entry we need "mask"
if (p_list[pll] != 100 && prios[ca, p_list[pll]] > 1)
need_mask = 1;
}
printf("\n");
printf("#define call_handlers_%s(num, ret, a1, a2, a3, a4, a5) \\\n", ca);
printf("({ \\\n");
if (need_mask)
printf(" uint64_t mask = 1ULL << num; \\\n");
printf(" ");
for (pl = 1; pl <= n_prios[ca]; pl++) {
if (prios[ca, p_list[pl]] > 1) {
if (pl < n_prios[ca]) {
printf(" if ( likely(mask & (%s)) ) \\\n", prio_mask[ca, p_list[pl]]);
printf(" { \\\n");
}
if (prios[ca, p_list[pl]] == 2) {
fnd = 0;
for (i = 1; i <= nc; i++)
if (call[i] == ca && call_prio[i] == p_list[pl]) {
fnd++;
if (fnd == 1)
printf(" if ( num == __HYPERVISOR_%s ) \\\n", fn[call_fn[i]]);
else
printf(" else \\\n");
do_call(call_fn[i], call_p[i]);
}
} else {
do_switch(ca, p_list[pl]);
}
if (pl < n_prios[ca])
printf(" } \\\n");
} else {
for (i = 1; i <= nc; i++)
if (call[i] == ca && call_prio[i] == p_list[pl]) {
printf("if ( likely(num == __HYPERVISOR_%s) ) \\\n", fn[call_fn[i]]);
do_call(call_fn[i], call_p[i]);
}
}
if (pl < n_prios[ca] || prios[ca, p_list[pl]] <= 2)
printf(" else \\\n");
}
if (prios[ca, p_list[n_prios[ca]]] <= 2) {
printf("\\\n");
printf(" ret = -ENOSYS; \\\n");
}
printf("})\n");
delete p_list;
printf("\n");
printf("#define hypercall_args_%s \\\n", ca);
printf("{ \\\n");
for (i = 1; i <= nc; i++)
if (call[i] == ca)
printf("[__HYPERVISOR_%s] = %d, \\\n", fn[call_fn[i]], n_args[call_fn[i]]);
printf("}\n");
}
}
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