search for: switch_to_kernel

Hi, I implemented my own Hypercall in xen. Now I wish my application under dom0 could talk to Xen via my hypercall. Currently, I make a stub in dom0''s kernel, which works as a proxy to forward the request. So, my application first makes a system call to dom0, which then makes hypercall to xen. Is this design necessary? May I call hypercalls from user application under dom0 directly?

...and PV Linux guest are all 64-bit (1) If a guest app uses "syscall" instruction to launch a system call to the guest kernel, is that behavior intercepted by Xen by default? If yes, could someone please point me to the related code in Xen for this interception? (anything to do with "switch_to_kernel in xen/arch/x86/x86_64/entry.S"?) If no, then how could I intercept that instruction in this case? (2) If a guest app uses "int 0x80" to launch a system call, then is it true that after "init_int80_direct_trap," the int 0x80 is no longer intercepted by Xen, and the app can...

...entry.S =================================================================== --- 2007-08-08.orig/xen/arch/x86/x86_64/entry.S 2007-07-04 12:13:16.000000000 +0200 +++ 2007-08-08/xen/arch/x86/x86_64/entry.S 2007-08-08 11:37:08.000000000 +0200 @@ -26,15 +26,19 @@ ALIGN /* %rbx: struct vcpu */ switch_to_kernel: - leaq VCPU_trap_bounce(%rbx),%rdx + cmpw $FLAT_USER_CS32,UREGS_cs(%rsp) movq VCPU_syscall_addr(%rbx),%rax + leaq VCPU_trap_bounce(%rbx),%rdx + cmoveq VCPU_syscall32_addr(%rbx),%rax + btl $_VGCF_syscall_disables_events,VCPU_guest_context_flags(%rbx...