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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH for-4.20] hvmloader: Rework hypercall infrastructure
Right now, the hypercall page is at a hardcoded physical address, and making
hypercalls involves indirect calls to compile-time constant addresses.
e.g. HYPERCALL_memory_op is:
mov $0x80180,%eax
call *%eax
Instead, import the hypercall infrastructure from XTF to have hypercall_page[]
fully within the hvmloader image, and prepared at compile time rather than
runtime. This uses direct calls, so HYPERCALL_memory_op now disassembles as:
call 132180 <HYPERCALL_memory_op>
which is faster and clearer.
Remove the loop over multiple hypercall pages. It was long ago realised to be
an unworkable design, and eax fixed in the ABI to 1.
Pass -z noexecstack to LD to stop newer bintuils complaining about the absence
of .note.GNU-stack. hvmloader is not a regular binary, and in fact its stack
is always executable owing to operating in unpaged mode.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
There doesn't appear to be any sensible AFLAGS infrastructure to set
-D__ASSEMBLY__. Opecoding it once seemed like the least bad option.
---
tools/firmware/hvmloader/Makefile | 3 +
tools/firmware/hvmloader/config.h | 1 -
tools/firmware/hvmloader/hvmloader.c | 7 +-
tools/firmware/hvmloader/hvmloader.lds | 4 +-
tools/firmware/hvmloader/hypercall.h | 121 ++++++----------------
tools/firmware/hvmloader/hypercall_page.S | 67 ++++++++++++
6 files changed, 105 insertions(+), 98 deletions(-)
create mode 100644 tools/firmware/hvmloader/hypercall_page.S
diff --git a/tools/firmware/hvmloader/Makefile
b/tools/firmware/hvmloader/Makefile
index 84cba171cd6b..0e1dce26b342 100644
--- a/tools/firmware/hvmloader/Makefile
+++ b/tools/firmware/hvmloader/Makefile
@@ -34,6 +34,7 @@ OBJS = hvmloader.o mp_tables.o util.o smbios.o
OBJS += smp.o cacheattr.o xenbus.o vnuma.o
OBJS += e820.o pci.o pir.o ctype.o
OBJS += hvm_param.o
+OBJS += hypercall_page.o
OBJS += ovmf.o seabios.o
ifeq ($(debug),y)
OBJS += tests.o
@@ -64,6 +65,7 @@ endif
# Suppress the warning about LOAD segments with RWX permissions, as what we
# build isn't a normal user-mode executable.
LDFLAGS-$(call ld-option,--warn-rwx-segments) := --no-warn-rwx-segments
+LDFLAGS-y += -z noexecstack
.PHONY: all
all: hvmloader
@@ -74,6 +76,7 @@ acpi:
rombios.o: roms.inc
smbios.o: CFLAGS += -D__SMBIOS_DATE__="\"$(SMBIOS_REL_DATE)\""
+hypercall_page.o: CFLAGS += -D__ASSEMBLY__
ACPI_PATH = ../../libacpi
DSDT_FILES = dsdt_anycpu.c dsdt_15cpu.c dsdt_anycpu_qemu_xen.c
diff --git a/tools/firmware/hvmloader/config.h
b/tools/firmware/hvmloader/config.h
index cd716bf39245..4ff7aa9d4483 100644
--- a/tools/firmware/hvmloader/config.h
+++ b/tools/firmware/hvmloader/config.h
@@ -64,7 +64,6 @@ extern bool acpi_enabled;
/* Memory map. */
#define SCRATCH_PHYSICAL_ADDRESS 0x00010000
-#define HYPERCALL_PHYSICAL_ADDRESS 0x00080000
#define VGABIOS_PHYSICAL_ADDRESS 0x000C0000
#define HVMLOADER_PHYSICAL_ADDRESS 0x00100000
/* Special BIOS mappings, etc. are allocated from here upwards... */
diff --git a/tools/firmware/hvmloader/hvmloader.c
b/tools/firmware/hvmloader/hvmloader.c
index f8af88fabf24..cd81eb412840 100644
--- a/tools/firmware/hvmloader/hvmloader.c
+++ b/tools/firmware/hvmloader/hvmloader.c
@@ -120,7 +120,6 @@ bool acpi_enabled;
static void init_hypercalls(void)
{
uint32_t eax, ebx, ecx, edx;
- unsigned long i;
char signature[13];
xen_extraversion_t extraversion;
uint32_t base;
@@ -142,8 +141,7 @@ static void init_hypercalls(void)
/* Fill in hypercall transfer pages. */
cpuid(base + 2, &eax, &ebx, &ecx, &edx);
- for ( i = 0; i < eax; i++ )
- wrmsr(ebx, HYPERCALL_PHYSICAL_ADDRESS + (i << 12) + i);
+ wrmsr(ebx, (unsigned long)hypercall_page);
/* Print version information. */
cpuid(base + 1, &eax, &ebx, &ecx, &edx);
@@ -324,9 +322,6 @@ int main(void)
const struct bios_config *bios;
const struct hvm_modlist_entry *bios_module;
- /* Initialise hypercall stubs with RET, rendering them no-ops. */
- memset((void *)HYPERCALL_PHYSICAL_ADDRESS, 0xc3 /* RET */, PAGE_SIZE);
-
printf("HVM Loader\n");
BUG_ON(hvm_start_info->magic != XEN_HVM_START_MAGIC_VALUE);
diff --git a/tools/firmware/hvmloader/hvmloader.lds
b/tools/firmware/hvmloader/hvmloader.lds
index edb1a12dc305..559cd2107f6a 100644
--- a/tools/firmware/hvmloader/hvmloader.lds
+++ b/tools/firmware/hvmloader/hvmloader.lds
@@ -7,9 +7,9 @@ SECTIONS
* NB: there's no need to use the AT keyword in order to set the LMA, by
* default the linker will use VMA = LMA unless specified otherwise.
*/
- .text : { *(.text) *(.text.*) }
+ .text : { *(.text) *(.text.*)}
.rodata : { *(.rodata) *(.rodata.*) }
- .data : { *(.data) *(.data.*) }
+ .data : { *(.data) *(.data.*) *(.hcall) }
.bss : { *(.bss) *(.bss.*) }
_end = .;
}
diff --git a/tools/firmware/hvmloader/hypercall.h
b/tools/firmware/hvmloader/hypercall.h
index 5368c3072007..a55051c5350f 100644
--- a/tools/firmware/hvmloader/hypercall.h
+++ b/tools/firmware/hvmloader/hypercall.h
@@ -35,148 +35,91 @@
#include <xen/xen.h>
#include "config.h"
-#define hcall_addr(name) \
- ((unsigned long)HYPERCALL_PHYSICAL_ADDRESS + __HYPERVISOR_##name * 32)
-
-#define _hypercall0(type, name) \
-({ \
- long __res; \
- asm volatile ( \
- "call *%%eax" \
- : "=a" (__res) \
- : "0" (hcall_addr(name)) \
- : "memory" ); \
- (type)__res; \
-})
-
-#define _hypercall1(type, name, a1) \
-({ \
- long __res, __ign1; \
- asm volatile ( \
- "call *%%eax" \
- : "=a" (__res), "=b" (__ign1) \
- : "0" (hcall_addr(name)), \
- "1" ((long)(a1)) \
- : "memory" ); \
- (type)__res; \
-})
-
-#define _hypercall2(type, name, a1, a2) \
-({ \
- long __res, __ign1, __ign2; \
- asm volatile ( \
- "call *%%eax" \
- : "=a" (__res), "=b" (__ign1), "=c" (__ign2) \
- : "0" (hcall_addr(name)), \
- "1" ((long)(a1)), "2" ((long)(a2)) \
- : "memory" ); \
- (type)__res; \
-})
-
-#define _hypercall3(type, name, a1, a2, a3) \
-({ \
- long __res, __ign1, __ign2, __ign3; \
- asm volatile ( \
- "call *%%eax" \
- : "=a" (__res), "=b" (__ign1), "=c" (__ign2), \
- "=d" (__ign3) \
- : "0" (hcall_addr(name)), \
- "1" ((long)(a1)), "2" ((long)(a2)), \
- "3" ((long)(a3)) \
- : "memory" ); \
- (type)__res; \
-})
-
-#define _hypercall4(type, name, a1, a2, a3, a4) \
-({ \
- long __res, __ign1, __ign2, __ign3, __ign4; \
- asm volatile ( \
- "call *%%eax" \
- : "=a" (__res), "=b" (__ign1), "=c" (__ign2), \
- "=d" (__ign3), "=S" (__ign4) \
- : "0" (hcall_addr(name)), \
- "1" ((long)(a1)), "2" ((long)(a2)), \
- "3" ((long)(a3)), "4" ((long)(a4)) \
- : "memory" ); \
- (type)__res; \
-})
-
-#define _hypercall5(type, name, a1, a2, a3, a4, a5) \
-({ \
- long __res, __ign1, __ign2, __ign3, __ign4, __ign5; \
- asm volatile ( \
- "call *%%eax" \
- : "=a" (__res), "=b" (__ign1), "=c" (__ign2), \
- "=d" (__ign3), "=S" (__ign4), "=D" (__ign5) \
- : "0" (hcall_addr(name)), \
- "1" ((long)(a1)), "2" ((long)(a2)), \
- "3" ((long)(a3)), "4" ((long)(a4)), \
- "5" ((long)(a5)) \
- : "memory" ); \
- (type)__res; \
-})
+extern const char hypercall_page[];
+
+#define _hypercall2(type, hcall, a1, a2) \
+ ({ \
+ long res, _a1 = (long)(a1), _a2 = (long)(a2); \
+ asm volatile ( \
+ "call hypercall_page + %c[offset]" \
+ : "=a" (res), "+b" (_a1), "+c" (_a2) \
+ : [offset] "i" (hcall * 32) \
+ : "memory" ); \
+ (type)res; \
+ })
+
+#define _hypercall3(type, hcall, a1, a2, a3) \
+ ({ \
+ long res, _a1 = (long)(a1), _a2 = (long)(a2), _a3 = (long)(a3); \
+ asm volatile ( \
+ "call hypercall_page + %c[offset]" \
+ : "=a" (res), "+b" (_a1), "+c" (_a2), "+d" (_a3) \
+ : [offset] "i" (hcall * 32) \
+ : "memory" ); \
+ (type)res; \
+ })
static inline int
hypercall_sched_op(
int cmd, void *arg)
{
- return _hypercall2(int, sched_op, cmd, arg);
+ return _hypercall2(int, __HYPERVISOR_sched_op, cmd, arg);
}
static inline int
hypercall_memory_op(
unsigned int cmd, void *arg)
{
- return _hypercall2(int, memory_op, cmd, arg);
+ return _hypercall2(int, __HYPERVISOR_memory_op, cmd, arg);
}
static inline int
hypercall_multicall(
void *call_list, int nr_calls)
{
- return _hypercall2(int, multicall, call_list, nr_calls);
+ return _hypercall2(int, __HYPERVISOR_multicall, call_list, nr_calls);
}
static inline int
hypercall_event_channel_op(
int cmd, void *arg)
{
- return _hypercall2(int, event_channel_op, cmd, arg);
+ return _hypercall2(int, __HYPERVISOR_event_channel_op, cmd, arg);
}
static inline int
hypercall_xen_version(
int cmd, void *arg)
{
- return _hypercall2(int, xen_version, cmd, arg);
+ return _hypercall2(int, __HYPERVISOR_xen_version, cmd, arg);
}
static inline int
hypercall_console_io(
int cmd, int count, char *str)
{
- return _hypercall3(int, console_io, cmd, count, str);
+ return _hypercall3(int, __HYPERVISOR_console_io, cmd, count, str);
}
static inline int
hypercall_vm_assist(
unsigned int cmd, unsigned int type)
{
- return _hypercall2(int, vm_assist, cmd, type);
+ return _hypercall2(int, __HYPERVISOR_vm_assist, cmd, type);
}
static inline int
hypercall_vcpu_op(
int cmd, int vcpuid, void *extra_args)
{
- return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
+ return _hypercall3(int, __HYPERVISOR_vcpu_op, cmd, vcpuid, extra_args);
}
static inline int
hypercall_hvm_op(
int cmd, void *arg)
{
- return _hypercall2(int, hvm_op, cmd, arg);
+ return _hypercall2(int, __HYPERVISOR_hvm_op, cmd, arg);
}
#endif /* __HVMLOADER_HYPERCALL_H__ */
diff --git a/tools/firmware/hvmloader/hypercall_page.S
b/tools/firmware/hvmloader/hypercall_page.S
new file mode 100644
index 000000000000..75428591d19a
--- /dev/null
+++ b/tools/firmware/hvmloader/hypercall_page.S
@@ -0,0 +1,67 @@
+#include <xen/xen.h>
+
+ .section ".hcall", "aw"
+ .align 4096
+
+ .globl hypercall_page
+hypercall_page:
+ /* Poisoned with `ret` for safety before hypercalls are set up. */
+ .fill 4096, 1, 0xc3
+ .type hypercall_page, STT_OBJECT
+ .size hypercall_page, 4096
+
+#define DECLARE_HYPERCALL(name)
\
+ .globl HYPERCALL_ ## name;
\
+ .type HYPERCALL_ ## name, STT_FUNC;
\
+ .size HYPERCALL_ ## name, 32;
\
+ .set HYPERCALL_ ## name, hypercall_page + __HYPERVISOR_ ## name * 32
+
+DECLARE_HYPERCALL(set_trap_table)
+DECLARE_HYPERCALL(mmu_update)
+DECLARE_HYPERCALL(set_gdt)
+DECLARE_HYPERCALL(stack_switch)
+DECLARE_HYPERCALL(set_callbacks)
+DECLARE_HYPERCALL(fpu_taskswitch)
+DECLARE_HYPERCALL(sched_op_compat)
+DECLARE_HYPERCALL(platform_op)
+DECLARE_HYPERCALL(set_debugreg)
+DECLARE_HYPERCALL(get_debugreg)
+DECLARE_HYPERCALL(update_descriptor)
+DECLARE_HYPERCALL(memory_op)
+DECLARE_HYPERCALL(multicall)
+DECLARE_HYPERCALL(update_va_mapping)
+DECLARE_HYPERCALL(set_timer_op)
+DECLARE_HYPERCALL(event_channel_op_compat)
+DECLARE_HYPERCALL(xen_version)
+DECLARE_HYPERCALL(console_io)
+DECLARE_HYPERCALL(physdev_op_compat)
+DECLARE_HYPERCALL(grant_table_op)
+DECLARE_HYPERCALL(vm_assist)
+DECLARE_HYPERCALL(update_va_mapping_otherdomain)
+DECLARE_HYPERCALL(iret)
+DECLARE_HYPERCALL(vcpu_op)
+DECLARE_HYPERCALL(set_segment_base)
+DECLARE_HYPERCALL(mmuext_op)
+DECLARE_HYPERCALL(xsm_op)
+DECLARE_HYPERCALL(nmi_op)
+DECLARE_HYPERCALL(sched_op)
+DECLARE_HYPERCALL(callback_op)
+DECLARE_HYPERCALL(xenoprof_op)
+DECLARE_HYPERCALL(event_channel_op)
+DECLARE_HYPERCALL(physdev_op)
+DECLARE_HYPERCALL(hvm_op)
+DECLARE_HYPERCALL(sysctl)
+DECLARE_HYPERCALL(domctl)
+DECLARE_HYPERCALL(kexec_op)
+DECLARE_HYPERCALL(tmem_op)
+DECLARE_HYPERCALL(argo_op)
+DECLARE_HYPERCALL(xenpmu_op)
+
+DECLARE_HYPERCALL(arch_0)
+DECLARE_HYPERCALL(arch_1)
+DECLARE_HYPERCALL(arch_2)
+DECLARE_HYPERCALL(arch_3)
+DECLARE_HYPERCALL(arch_4)
+DECLARE_HYPERCALL(arch_5)
+DECLARE_HYPERCALL(arch_6)
+DECLARE_HYPERCALL(arch_7)
--
2.39.2
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