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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] x86/traps: Move subarch_percpu_traps_init() into traps-setup.c
commit 327ca0b54524de547417005e65ea168a6ed222be
Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Wed Jan 8 11:51:06 2025 +0000
Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Fri Aug 15 11:13:41 2025 +0100
x86/traps: Move subarch_percpu_traps_init() into traps-setup.c
... along with the supporting functions. Switch to Xen coding style, and
make
static as there are no external callers.
Rename to legacy_syscall_init() as a more accurate name.
Swap wrmsr{,l}() for wrmsrns(). No serialisation is needed at this point.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
xen/arch/x86/include/asm/system.h | 2 -
xen/arch/x86/traps-setup.c | 97 ++++++++++++++++++++++++++++++++++++++-
xen/arch/x86/x86_64/traps.c | 92 -------------------------------------
3 files changed, 95 insertions(+), 96 deletions(-)
diff --git a/xen/arch/x86/include/asm/system.h
b/xen/arch/x86/include/asm/system.h
index 3cdc56e4ba..6c2800d815 100644
--- a/xen/arch/x86/include/asm/system.h
+++ b/xen/arch/x86/include/asm/system.h
@@ -256,6 +256,4 @@ static inline int local_irq_is_enabled(void)
#define BROKEN_ACPI_Sx 0x0001
#define BROKEN_INIT_AFTER_S1 0x0002
-void subarch_percpu_traps_init(void);
-
#endif
diff --git a/xen/arch/x86/traps-setup.c b/xen/arch/x86/traps-setup.c
index d089833121..25581acf11 100644
--- a/xen/arch/x86/traps-setup.c
+++ b/xen/arch/x86/traps-setup.c
@@ -2,13 +2,15 @@
/*
* Configuration of event handling for all CPUs.
*/
+#include <xen/domain_page.h>
#include <xen/init.h>
#include <xen/param.h>
+#include <asm/endbr.h>
#include <asm/idt.h>
#include <asm/msr.h>
#include <asm/shstk.h>
-#include <asm/system.h>
+#include <asm/stubs.h>
#include <asm/traps.h>
DEFINE_PER_CPU_READ_MOSTLY(idt_entry_t *, idt);
@@ -19,6 +21,8 @@ static bool __initdata opt_ler;
boolean_param("ler", opt_ler);
void nocall entry_PF(void);
+void nocall lstar_enter(void);
+void nocall cstar_enter(void);
/*
* Sets up system tables and descriptors for IDT devliery.
@@ -132,6 +136,95 @@ static void load_system_tables(void)
BUG_ON(stack_bottom & 15);
}
+static unsigned int write_stub_trampoline(
+ unsigned char *stub, unsigned long stub_va,
+ unsigned long stack_bottom, unsigned long target_va)
+{
+ unsigned char *p = stub;
+
+ if ( cpu_has_xen_ibt )
+ {
+ place_endbr64(p);
+ p += 4;
+ }
+
+ /* Store guest %rax into %ss slot */
+ /* movabsq %rax, stack_bottom - 8 */
+ *p++ = 0x48;
+ *p++ = 0xa3;
+ *(uint64_t *)p = stack_bottom - 8;
+ p += 8;
+
+ /* Store guest %rsp in %rax */
+ /* movq %rsp, %rax */
+ *p++ = 0x48;
+ *p++ = 0x89;
+ *p++ = 0xe0;
+
+ /* Switch to Xen stack */
+ /* movabsq $stack_bottom - 8, %rsp */
+ *p++ = 0x48;
+ *p++ = 0xbc;
+ *(uint64_t *)p = stack_bottom - 8;
+ p += 8;
+
+ /* jmp target_va */
+ *p++ = 0xe9;
+ *(int32_t *)p = target_va - (stub_va + (p - stub) + 4);
+ p += 4;
+
+ /* Round up to a multiple of 16 bytes. */
+ return ROUNDUP(p - stub, 16);
+}
+
+static void legacy_syscall_init(void)
+{
+ unsigned long stack_bottom = get_stack_bottom();
+ unsigned long stub_va = this_cpu(stubs.addr);
+ unsigned char *stub_page;
+ unsigned int offset;
+
+ /* No PV guests? No need to set up SYSCALL/SYSENTER infrastructure. */
+ if ( !IS_ENABLED(CONFIG_PV) )
+ return;
+
+ stub_page = map_domain_page(_mfn(this_cpu(stubs.mfn)));
+
+ /*
+ * Trampoline for SYSCALL entry from 64-bit mode. The VT-x HVM vcpu
+ * context switch logic relies on the SYSCALL trampoline being at the
+ * start of the stubs.
+ */
+ wrmsrns(MSR_LSTAR, stub_va);
+ offset = write_stub_trampoline(stub_page + (stub_va & ~PAGE_MASK),
+ stub_va, stack_bottom,
+ (unsigned long)lstar_enter);
+ stub_va += offset;
+
+ if ( cpu_has_sep )
+ {
+ /* SYSENTER entry. */
+ wrmsrns(MSR_IA32_SYSENTER_ESP, stack_bottom);
+ wrmsrns(MSR_IA32_SYSENTER_EIP, (unsigned long)sysenter_entry);
+ wrmsrns(MSR_IA32_SYSENTER_CS, __HYPERVISOR_CS);
+ }
+
+ /* Trampoline for SYSCALL entry from compatibility mode. */
+ wrmsrns(MSR_CSTAR, stub_va);
+ offset += write_stub_trampoline(stub_page + (stub_va & ~PAGE_MASK),
+ stub_va, stack_bottom,
+ (unsigned long)cstar_enter);
+
+ /* Don't consume more than half of the stub space here. */
+ ASSERT(offset <= STUB_BUF_SIZE / 2);
+
+ unmap_domain_page(stub_page);
+
+ /* Common SYSCALL parameters. */
+ wrmsrns(MSR_STAR, XEN_MSR_STAR);
+ wrmsrns(MSR_SYSCALL_MASK, XEN_SYSCALL_MASK);
+}
+
static void __init init_ler(void)
{
unsigned int msr = 0;
@@ -235,7 +328,7 @@ void __init bsp_traps_reinit(void)
*/
void percpu_traps_init(void)
{
- subarch_percpu_traps_init();
+ legacy_syscall_init();
if ( cpu_has_xen_lbr )
wrmsrl(MSR_IA32_DEBUGCTLMSR, IA32_DEBUGCTLMSR_LBR);
diff --git a/xen/arch/x86/x86_64/traps.c b/xen/arch/x86/x86_64/traps.c
index 34adf55e48..81e64466e4 100644
--- a/xen/arch/x86/x86_64/traps.c
+++ b/xen/arch/x86/x86_64/traps.c
@@ -311,98 +311,6 @@ void asmlinkage noreturn do_double_fault(struct
cpu_user_regs *regs)
panic("DOUBLE FAULT -- system shutdown\n");
}
-static unsigned int write_stub_trampoline(
- unsigned char *stub, unsigned long stub_va,
- unsigned long stack_bottom, unsigned long target_va)
-{
- unsigned char *p = stub;
-
- if ( cpu_has_xen_ibt )
- {
- place_endbr64(p);
- p += 4;
- }
-
- /* Store guest %rax into %ss slot */
- /* movabsq %rax, stack_bottom - 8 */
- *p++ = 0x48;
- *p++ = 0xa3;
- *(uint64_t *)p = stack_bottom - 8;
- p += 8;
-
- /* Store guest %rsp in %rax */
- /* movq %rsp, %rax */
- *p++ = 0x48;
- *p++ = 0x89;
- *p++ = 0xe0;
-
- /* Switch to Xen stack */
- /* movabsq $stack_bottom - 8, %rsp */
- *p++ = 0x48;
- *p++ = 0xbc;
- *(uint64_t *)p = stack_bottom - 8;
- p += 8;
-
- /* jmp target_va */
- *p++ = 0xe9;
- *(int32_t *)p = target_va - (stub_va + (p - stub) + 4);
- p += 4;
-
- /* Round up to a multiple of 16 bytes. */
- return ROUNDUP(p - stub, 16);
-}
-
-void nocall lstar_enter(void);
-void nocall cstar_enter(void);
-
-void subarch_percpu_traps_init(void)
-{
- unsigned long stack_bottom = get_stack_bottom();
- unsigned long stub_va = this_cpu(stubs.addr);
- unsigned char *stub_page;
- unsigned int offset;
-
- /* No PV guests? No need to set up SYSCALL/SYSENTER infrastructure. */
- if ( !IS_ENABLED(CONFIG_PV) )
- return;
-
- stub_page = map_domain_page(_mfn(this_cpu(stubs.mfn)));
-
- /*
- * Trampoline for SYSCALL entry from 64-bit mode. The VT-x HVM vcpu
- * context switch logic relies on the SYSCALL trampoline being at the
- * start of the stubs.
- */
- wrmsrl(MSR_LSTAR, stub_va);
- offset = write_stub_trampoline(stub_page + (stub_va & ~PAGE_MASK),
- stub_va, stack_bottom,
- (unsigned long)lstar_enter);
- stub_va += offset;
-
- if ( cpu_has_sep )
- {
- /* SYSENTER entry. */
- wrmsrl(MSR_IA32_SYSENTER_ESP, stack_bottom);
- wrmsrl(MSR_IA32_SYSENTER_EIP, (unsigned long)sysenter_entry);
- wrmsr(MSR_IA32_SYSENTER_CS, __HYPERVISOR_CS, 0);
- }
-
- /* Trampoline for SYSCALL entry from compatibility mode. */
- wrmsrl(MSR_CSTAR, stub_va);
- offset += write_stub_trampoline(stub_page + (stub_va & ~PAGE_MASK),
- stub_va, stack_bottom,
- (unsigned long)cstar_enter);
-
- /* Don't consume more than half of the stub space here. */
- ASSERT(offset <= STUB_BUF_SIZE / 2);
-
- unmap_domain_page(stub_page);
-
- /* Common SYSCALL parameters. */
- wrmsrl(MSR_STAR, XEN_MSR_STAR);
- wrmsrl(MSR_SYSCALL_MASK, XEN_SYSCALL_MASK);
-}
-
/*
* Local variables:
* mode: C
--
generated by git-patchbot for /home/xen/git/xen.git#master
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