| Message ID | 1454267976-27242-3-git-send-email-mark.cave-ayland@ilande.co.uk |
|---|---|
| State | New |
| Headers | show |
On Sun, Jan 31, 2016 at 07:19:35PM +0000, Mark Cave-Ayland wrote: > This patch provides support for migration of the PPC guest timebase on non-PPC > host architectures (i.e those using QEMU's virtual emulated timebase). > > Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> We shouldn't need an explicit test for a ppc host. Instead we should never be touching any host-dependent ticks values, only using host side interfaces which work in realtime units like ns. Worse, the ppc host variants here will still be wrong if the host has a different timebase frequency to the guest, which will always be true for a g3beige (16MHz) on a modern ppc host (512 MHz). > --- > hw/ppc/ppc.c | 33 +++++++++++++++++++++++++++------ > 1 file changed, 27 insertions(+), 6 deletions(-) > > diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c > index 19f4570..9b80c1d 100644 > --- a/hw/ppc/ppc.c > +++ b/hw/ppc/ppc.c > @@ -832,6 +832,15 @@ static void cpu_ppc_set_tb_clk (void *opaque, uint32_t freq) > cpu_ppc_store_purr(cpu, 0x0000000000000000ULL); > } > > +static int host_cpu_is_ppc(void) > +{ > +#if defined(_ARCH_PPC) > + return -1; > +#else > + return 0; > +#endif > +} > + > static void timebase_pre_save(void *opaque) > { > PPCTimebase *tb = opaque; > @@ -844,11 +853,16 @@ static void timebase_pre_save(void *opaque) > } > > tb->time_of_the_day_ns = qemu_clock_get_ns(QEMU_CLOCK_HOST); > - /* > - * tb_offset is only expected to be changed by migration so > - * there is no need to update it from KVM here > - */ > - tb->guest_timebase = ticks + first_ppc_cpu->env.tb_env->tb_offset; > + > + if (host_cpu_is_ppc()) { > + /* > + * tb_offset is only expected to be changed by migration so > + * there is no need to update it from KVM here > + */ > + tb->guest_timebase = ticks + first_ppc_cpu->env.tb_env->tb_offset; > + } else { > + tb->guest_timebase = cpu_ppc_load_tbl(&first_ppc_cpu->env); > + } > } > > static int timebase_post_load(void *opaque, int version_id) > @@ -879,7 +893,14 @@ static int timebase_post_load(void *opaque, int version_id) > NANOSECONDS_PER_SECOND); > guest_tb = tb_remote->guest_timebase + migration_duration_tb; > > - tb_off_adj = guest_tb - cpu_get_host_ticks(); > + if (host_cpu_is_ppc()) { > + /* Hardware timebase */ > + tb_off_adj = guest_tb - cpu_get_host_ticks(); > + } else { > + /* Software timebase */ > + tb_off_adj = guest_tb - muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), > + freq, get_ticks_per_sec()); > + } > > tb_off = first_ppc_cpu->env.tb_env->tb_offset; > trace_ppc_tb_adjust(tb_off, tb_off_adj, tb_off_adj - tb_off,
diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c index 19f4570..9b80c1d 100644 --- a/hw/ppc/ppc.c +++ b/hw/ppc/ppc.c @@ -832,6 +832,15 @@ static void cpu_ppc_set_tb_clk (void *opaque, uint32_t freq) cpu_ppc_store_purr(cpu, 0x0000000000000000ULL); } +static int host_cpu_is_ppc(void) +{ +#if defined(_ARCH_PPC) + return -1; +#else + return 0; +#endif +} + static void timebase_pre_save(void *opaque) { PPCTimebase *tb = opaque; @@ -844,11 +853,16 @@ static void timebase_pre_save(void *opaque) } tb->time_of_the_day_ns = qemu_clock_get_ns(QEMU_CLOCK_HOST); - /* - * tb_offset is only expected to be changed by migration so - * there is no need to update it from KVM here - */ - tb->guest_timebase = ticks + first_ppc_cpu->env.tb_env->tb_offset; + + if (host_cpu_is_ppc()) { + /* + * tb_offset is only expected to be changed by migration so + * there is no need to update it from KVM here + */ + tb->guest_timebase = ticks + first_ppc_cpu->env.tb_env->tb_offset; + } else { + tb->guest_timebase = cpu_ppc_load_tbl(&first_ppc_cpu->env); + } } static int timebase_post_load(void *opaque, int version_id) @@ -879,7 +893,14 @@ static int timebase_post_load(void *opaque, int version_id) NANOSECONDS_PER_SECOND); guest_tb = tb_remote->guest_timebase + migration_duration_tb; - tb_off_adj = guest_tb - cpu_get_host_ticks(); + if (host_cpu_is_ppc()) { + /* Hardware timebase */ + tb_off_adj = guest_tb - cpu_get_host_ticks(); + } else { + /* Software timebase */ + tb_off_adj = guest_tb - muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), + freq, get_ticks_per_sec()); + } tb_off = first_ppc_cpu->env.tb_env->tb_offset; trace_ppc_tb_adjust(tb_off, tb_off_adj, tb_off_adj - tb_off,
This patch provides support for migration of the PPC guest timebase on non-PPC host architectures (i.e those using QEMU's virtual emulated timebase). Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> --- hw/ppc/ppc.c | 33 +++++++++++++++++++++++++++------ 1 file changed, 27 insertions(+), 6 deletions(-)