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vbox: save the guest FPU state before 'longjmp()' 

'longjmp()' restores the (partial) FPU state saved by 'setjmp()', so it's
necessary to save the guest FPU state before calling 'longjmp()'.

Fixes #1282
This commit is contained in:
Christian Prochaska 2014-10-24 23:23:16 +02:00 committed by Christian Helmuth
parent 6afba00ad6
commit e3fa8c9f22
1 changed files with 22 additions and 10 deletions
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32
repos/ports/src/virtualbox/nova/vcpu.h
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@ -73,7 +73,8 @@ class Vcpu_handler : public Vmm::Vcpu_dispatcher<pthread>
{
private:
X86FXSTATE _fpu_state __attribute__((aligned(0x10)));
X86FXSTATE _guest_fpu_state __attribute__((aligned(0x10)));
X86FXSTATE _emt_fpu_state __attribute__((aligned(0x10)));
Genode::Cap_connection _cap_connection;
Vmm::Vcpu_other_pd _vcpu;
@ -107,6 +108,16 @@ class Vcpu_handler : public Vmm::Vcpu_dispatcher<pthread>
INTERRUPT_STATE_NONE = 0U,
};
/*
* 'longjmp()' restores some FPU registers saved by 'setjmp()',
* so we need to save the guest FPU state before calling 'longjmp()'
*/
__attribute__((noreturn)) void _fpu_save_and_longjmp()
{
fpu_save(reinterpret_cast<char *>(&_guest_fpu_state));
longjmp(_env, 1);
}
protected:
struct {
@ -120,7 +131,8 @@ class Vcpu_handler : public Vmm::Vcpu_dispatcher<pthread>
void * _stack_reply;
jmp_buf _env;
void switch_to_hw(PCPUMCTX pCtx) {
void switch_to_hw()
{
unsigned long value;
if (!setjmp(_env)) {
@ -129,7 +141,6 @@ class Vcpu_handler : public Vmm::Vcpu_dispatcher<pthread>
}
}
__attribute__((noreturn)) void _default_handler()
{
Nova::Utcb * utcb = reinterpret_cast<Nova::Utcb *>(Thread_base::utcb());
@ -138,7 +149,7 @@ class Vcpu_handler : public Vmm::Vcpu_dispatcher<pthread>
Assert(!(utcb->inj_info & IRQ_INJ_VALID_MASK));
/* go back to re-compiler */
longjmp(_env, 1);
_fpu_save_and_longjmp();
}
__attribute__((noreturn)) void _recall_handler()
@ -162,7 +173,7 @@ class Vcpu_handler : public Vmm::Vcpu_dispatcher<pthread>
/* are we forced to go back to emulation mode ? */
if (!continue_hw_accelerated(utcb))
/* go back to emulation mode */
longjmp(_env, 1);
_fpu_save_and_longjmp();
/* check whether we have to request irq injection window */
utcb->mtd = 0;
@ -216,7 +227,7 @@ class Vcpu_handler : public Vmm::Vcpu_dispatcher<pthread>
/* emulator has to take over if fault region is not ram */
if (!pv)
longjmp(_env, 1);
_fpu_save_and_longjmp();
/* fault region is ram - so map it */
enum {
@ -675,7 +686,7 @@ class Vcpu_handler : public Vmm::Vcpu_dispatcher<pthread>
VMCPU_SET_STATE(pVCpu, VMCPUSTATE_STARTED_EXEC);
/* save current FPU state */
fpu_save(reinterpret_cast<char *>(&_fpu_state));
fpu_save(reinterpret_cast<char *>(&_emt_fpu_state));
/* write FPU state from pCtx to FPU registers */
fpu_load(reinterpret_cast<char *>(&pCtx->fpu));
/* tell kernel to transfer current fpu registers to vCPU */
@ -685,7 +696,7 @@ class Vcpu_handler : public Vmm::Vcpu_dispatcher<pthread>
_current_vcpu = pVCpu;
/* switch to hardware accelerated mode */
switch_to_hw(pCtx);
switch_to_hw();
Assert(utcb->actv_state == ACTIVITY_STATE_ACTIVE);
@ -693,9 +704,10 @@ class Vcpu_handler : public Vmm::Vcpu_dispatcher<pthread>
_current_vcpu = 0;
/* write FPU state of vCPU (in current FPU registers) to pCtx */
fpu_save(reinterpret_cast<char *>(&pCtx->fpu));
Genode::memcpy(&pCtx->fpu, &_guest_fpu_state, sizeof(X86FXSTATE));
/* load saved FPU state of EMT thread */
fpu_load(reinterpret_cast<char *>(&_fpu_state));
fpu_load(reinterpret_cast<char *>(&_emt_fpu_state));
// CPUMSetChangedFlags(pVCpu, CPUM_CHANGED_GLOBAL_TLB_FLUSH);