X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Flguest%2Fx86%2Fcore.c;h=2e554a4ab33792dc7e92318cafe11a75e6c35246;hb=97e6722b8d6b5880c4d5751127d5083b1b7df27d;hp=5126d5d9ea0e8d8d97fa0eaf47ed22216329328b;hpb=670e23ceb1aefacfe9aeccfc871e28e9cf973286;p=linux-2.6 diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c index 5126d5d9ea..2e554a4ab3 100644 --- a/drivers/lguest/x86/core.c +++ b/drivers/lguest/x86/core.c @@ -176,7 +176,7 @@ void lguest_arch_run_guest(struct lg_cpu *cpu) * we set it now, so we can trap and pass that trap to the Guest if it * uses the FPU. */ if (cpu->ts) - lguest_set_ts(); + unlazy_fpu(current); /* SYSENTER is an optimized way of doing system calls. We can't allow * it because it always jumps to privilege level 0. A normal Guest @@ -196,6 +196,10 @@ void lguest_arch_run_guest(struct lg_cpu *cpu) * trap made the switcher code come back, and an error code which some * traps set. */ + /* Restore SYSENTER if it's supposed to be on. */ + if (boot_cpu_has(X86_FEATURE_SEP)) + wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0); + /* If the Guest page faulted, then the cr2 register will tell us the * bad virtual address. We have to grab this now, because once we * re-enable interrupts an interrupt could fault and thus overwrite @@ -203,13 +207,12 @@ void lguest_arch_run_guest(struct lg_cpu *cpu) if (cpu->regs->trapnum == 14) cpu->arch.last_pagefault = read_cr2(); /* Similarly, if we took a trap because the Guest used the FPU, - * we have to restore the FPU it expects to see. */ + * we have to restore the FPU it expects to see. + * math_state_restore() may sleep and we may even move off to + * a different CPU. So all the critical stuff should be done + * before this. */ else if (cpu->regs->trapnum == 7) math_state_restore(); - - /* Restore SYSENTER if it's supposed to be on. */ - if (boot_cpu_has(X86_FEATURE_SEP)) - wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0); } /*H:130 Now we've examined the hypercall code; our Guest can make requests.