From: Patrick G. Bridges Date: Fri, 24 Feb 2012 17:56:12 +0000 (-0700) Subject: More changed files X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=commitdiff_plain;h=85072cab5137e1db9aa3f8e9b8cc82887b72d9db;p=palacios.releases.git More changed files --- diff --git a/palacios/include/palacios/vmm_time.h b/palacios/include/palacios/vmm_time.h index 1e3c7fd..a3ef556 100644 --- a/palacios/include/palacios/vmm_time.h +++ b/palacios/include/palacios/vmm_time.h @@ -33,7 +33,8 @@ struct guest_info; /* Per-VM time information */ struct v3_time { - uint32_t td_mult; + uint32_t td_mult; /* Currently unused! */ + char follow_host_time; }; /* Per-core time information */ @@ -49,7 +50,7 @@ struct vm_core_time { uint64_t initial_time; // Host time when VMM started. uint64_t enter_time; // Host time the guest was last entered - uint64_t exit_time; // Host time the the VM was exited to + uint64_t pause_time; // Host time when we went into the VMM struct v3_msr tsc_aux; // Auxilliary MSR for RDTSCP // Installed Timers slaved off of the guest monotonic TSC @@ -86,11 +87,9 @@ int v3_start_time(struct guest_info * core); int v3_time_enter_vm(struct guest_info * core); int v3_time_exit_vm(struct guest_info * core, uint64_t * guest_cycles); -int v3_pause_time(struct guest_info * core); -int v3_resume_time(struct guest_info * core); int v3_offset_time(struct guest_info * core, sint64_t offset); - -int v3_adjust_time(struct guest_info * core); +int v3_skip_time(struct guest_info * core); +int v3_advance_time(struct guest_info * core); // Basic functions for attaching timers to the passage of time - these timers // should eventually specify their accuracy and resolution. diff --git a/palacios/src/palacios/svm.c b/palacios/src/palacios/svm.c index 9a03aa6..8eb1f61 100644 --- a/palacios/src/palacios/svm.c +++ b/palacios/src/palacios/svm.c @@ -537,17 +537,13 @@ int v3_svm_enter(struct guest_info * info) { // Conditionally yield the CPU if the timeslice has expired v3_yield_cond(info); - // Perform any additional yielding needed for time adjustment - v3_adjust_time(info); - - - // disable global interrupts for vm state transition v3_clgi(); // Update timer devices after being in the VM, with interupts // disabled, but before doing IRQ updates, so that any interrupts they //raise get seen immediately. + v3_advance_time(info); v3_update_timers(info); // Synchronize the guest state to the VMCB diff --git a/palacios/src/palacios/vmm_halt.c b/palacios/src/palacios/vmm_halt.c index bfe2e5a..06b393c 100644 --- a/palacios/src/palacios/vmm_halt.c +++ b/palacios/src/palacios/vmm_halt.c @@ -42,10 +42,11 @@ int v3_handle_halt(struct guest_info * info) { while (!v3_intr_pending(info)) { /* Since we're in an exit, time is already paused here, so no need to pause again. */ - // V3_Print("palacios: halt->yield\n"); - - v3_yield(info); + /* Yield, allowing time to pass while yielded */ + v3_yield(info); + v3_advance_time(info); + v3_disable_ints(); v3_update_timers(info); v3_enable_ints(); diff --git a/palacios/src/palacios/vmm_time.c b/palacios/src/palacios/vmm_time.c index 1c7b83e..727de3f 100644 --- a/palacios/src/palacios/vmm_time.c +++ b/palacios/src/palacios/vmm_time.c @@ -91,7 +91,7 @@ int v3_start_time(struct guest_info * info) { uint64_t t = v3_get_host_time(&info->time_state); info->time_state.enter_time = 0; - info->time_state.exit_time = t; + info->time_state.pause_time = t; info->time_state.initial_time = t; info->yield_start_cycle = t; @@ -106,116 +106,35 @@ int v3_start_time(struct guest_info * info) { int v3_offset_time( struct guest_info * info, sint64_t offset ) { struct vm_core_time * time_state = &(info->time_state); - PrintDebug("Adding additional offset of %lld to guest time.\n", offset); time_state->guest_cycles += offset; return 0; } -#ifdef V3_CONFIG_TIME_DILATION -static uint64_t compute_target_host_time(struct guest_info * info, uint64_t guest_time) -{ - struct vm_core_time * time_state = &(info->time_state); - uint64_t guest_elapsed, desired_elapsed; - - guest_elapsed = (guest_time - time_state->initial_time); - desired_elapsed = (guest_elapsed * time_state->host_cpu_freq) / time_state->guest_cpu_freq; - return time_state->initial_time + desired_elapsed; -} - -static uint64_t compute_target_guest_time(struct guest_info *info) -{ - struct vm_core_time * time_state = &(info->time_state); - uint64_t host_elapsed, desired_elapsed; - - host_elapsed = v3_get_host_time(time_state) - time_state->initial_time; - desired_elapsed = (host_elapsed * time_state->guest_cpu_freq) / time_state->host_cpu_freq; - - return time_state->initial_time + desired_elapsed; - -} - -/* Yield time in the host to deal with a guest that wants to run slower than - * the native host cycle frequency */ -static int yield_host_time(struct guest_info * info) { - struct vm_core_time * time_state = &(info->time_state); - uint64_t host_time, target_host_time; - uint64_t guest_time, old_guest_time; - - /* Now, let the host run while the guest is stopped to make the two - * sync up. Note that this doesn't assume that guest time is stopped; - * the offsetting in the next step will change add an offset to guest - * time to account for the time paused even if the geust isn't - * usually paused in the VMM. */ - host_time = v3_get_host_time(time_state); - old_guest_time = v3_get_guest_time(time_state); - target_host_time = compute_target_host_time(info, old_guest_time); - - while (target_host_time > host_time) { - v3_yield(info); - host_time = v3_get_host_time(time_state); +int v3_skip_time(struct guest_info * info) { + if (info->vm_info->time_state.follow_host_time) { + PrintError("Cannot skip host time passage while slaved to host clock.\n"); + return 1; + } else { + info->time_state.pause_time = v3_get_host_time(&info->time_state); } - - guest_time = v3_get_guest_time(time_state); - - /* We do *not* assume the guest timer was paused in the VM. If it was - * this offseting is 0. If it wasn't, we need this. */ - v3_offset_time(info, (sint64_t)(old_guest_time - guest_time)); - return 0; } -static int skew_guest_time(struct guest_info * info) { - struct vm_core_time * time_state = &(info->time_state); - uint64_t target_guest_time, guest_time; - /* Now the host may have gotten ahead of the guest because - * yielding is a coarse grained thing. Figure out what guest time - * we want to be at, and use the use the offsetting mechanism in - * the VMM to make the guest run forward. We limit *how* much we skew - * it forward to prevent the guest time making large jumps, - * however. */ - target_guest_time = compute_target_guest_time(info); - guest_time = v3_get_guest_time(time_state); - - if (guest_time < target_guest_time) { - sint64_t max_skew, desired_skew, skew; - - if (time_state->enter_time) { - /* Limit forward skew to 10% of the amount the guest has - * run since we last could skew time */ - max_skew = (sint64_t)(guest_time - time_state->enter_time) / 10; - } else { - max_skew = 0; - } - - desired_skew = (sint64_t)(target_guest_time - guest_time); - skew = desired_skew > max_skew ? max_skew : desired_skew; - PrintDebug("Guest %lld cycles behind where it should be.\n", - desired_skew); - PrintDebug("Limit on forward skew is %lld. Skewing forward %lld.\n", - max_skew, skew); - - v3_offset_time(info, skew); +int v3_advance_time(struct guest_info * info) { + uint64_t t = v3_get_host_time(&info->time_state); + if (info->vm_info->time_state.follow_host_time) { + /* How many guest cycles should have elapsed? */ + sint64_t host_elapsed = t - info->time_state.initial_time; + sint64_t guest_target = (host_elapsed * info->time_state.guest_cpu_freq) / info->time_state.host_cpu_freq; + sint64_t cycle_lag = guest_target - info->time_state.guest_cycles; + v3_offset_time(info, cycle_lag); + } else { + v3_offset_time(info, (sint64_t)(t - info->time_state.pause_time)); } + info->time_state.pause_time = t; return 0; } -#endif /* V3_CONFIG_TIME_DILATION */ - -// Control guest time in relation to host time so that the two stay -// appropriately synchronized to the extent possible. -int v3_adjust_time(struct guest_info * info) { - -#ifdef V3_CONFIG_TIME_DILATION - /* First deal with yielding if we want to slow down the guest */ - yield_host_time(info); - - /* Now, if the guest is too slow, (either from excess yielding above, - * or because the VMM is doing something that takes a long time to emulate) - * allow guest time to jump forward a bit */ - skew_guest_time(info); -#endif - return 0; -} /* Called immediately upon entry in the the VMM */ int @@ -223,12 +142,12 @@ v3_time_exit_vm( struct guest_info * info, uint64_t * guest_cycles ) { struct vm_core_time * time_state = &(info->time_state); - time_state->exit_time = v3_get_host_time(time_state); + time_state->pause_time = v3_get_host_time(time_state); if (guest_cycles) { time_state->guest_cycles += *guest_cycles; } else { - uint64_t cycles_exec; - cycles_exec = time_state->exit_time - time_state->enter_time; + sint64_t cycles_exec; + cycles_exec = (sint64_t)(time_state->pause_time - time_state->enter_time); time_state->guest_cycles += cycles_exec; } return 0; @@ -239,15 +158,10 @@ int v3_time_enter_vm( struct guest_info * info ) { struct vm_core_time * time_state = &(info->time_state); - uint64_t host_time, vmm_cycles; + uint64_t host_time = v3_get_host_time(&info->time_state); - host_time = v3_get_host_time(time_state); + v3_advance_time(info); time_state->enter_time = host_time; - vmm_cycles = host_time - time_state->exit_time; - /* XXX How do we want to take into account host/guest CPU speed differences - * and time dilation here? Probably time just won't advance in the VMM in that - * case so its irrelvant XXX */ - time_state->guest_cycles += vmm_cycles; return 0; } @@ -406,7 +320,7 @@ static int tsc_msr_write_hook(struct guest_info *info, uint_t msr_num, new_tsc = (((uint64_t)msr_val.hi) << 32) | (uint64_t)msr_val.lo; guest_time = v3_get_guest_time(time_state); - time_state->tsc_guest_offset = (sint64_t)new_tsc - (sint64_t)guest_time; + time_state->tsc_guest_offset = (sint64_t)(new_tsc - guest_time); return 0; } @@ -438,6 +352,8 @@ int v3_init_time_vm(struct v3_vm_info * vm) { vm->time_state.td_mult = 1; PrintDebug("Setting base time dilation factor to %d.\n", vm->time_state.td_mult); + vm->time_state.follow_host_time = 1; + PrintDebug("Locking guest time to host time.\n"); return ret; } @@ -478,7 +394,7 @@ void v3_init_time_core(struct guest_info * info) { time_state->last_update = 0; time_state->tsc_guest_offset = 0; time_state->enter_time = 0; - time_state->exit_time = 0; + time_state->pause_time = 0; time_state->guest_cycles = 0; INIT_LIST_HEAD(&(time_state->timers)); diff --git a/palacios/src/palacios/vmx.c b/palacios/src/palacios/vmx.c index 2eb4ae1..a30cb4e 100644 --- a/palacios/src/palacios/vmx.c +++ b/palacios/src/palacios/vmx.c @@ -856,9 +856,6 @@ int v3_vmx_enter(struct guest_info * info) { // Conditionally yield the CPU if the timeslice has expired v3_yield_cond(info); - // Perform any additional yielding needed for time adjustment - v3_adjust_time(info); - // disable global interrupts for vm state transition v3_disable_ints(); @@ -866,6 +863,7 @@ int v3_vmx_enter(struct guest_info * info) { // of the time in the VM is accounted for as possible. Also do it before // updating IRQ entry state so that any interrupts the timers raise get // handled on the next VM entry. Must be done with interrupts disabled. + v3_advance_time(info); v3_update_timers(info); if (vmcs_store() != vmx_info->vmcs_ptr_phys) {