| Message ID | 20180604152941.20374-10-peter.maydell@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | iommu: support txattrs, support TCG execution, implement TZ MPC | expand |
Peter Maydell <peter.maydell@linaro.org> writes: > For the IoTKit MPC support, we need to wire together the > interrupt outputs of 17 MPCs; this exceeds the current > value of MAX_OR_LINES. Increase MAX_OR_LINES to 32 (which > should be enough for anyone). > > The tricky part is retaining the migration compatibility for > existing OR gates; we add a subsection which is only used > for larger OR gates, and define it such that we can freely > increase MAX_OR_LINES in future (or even move to a dynamically > allocated levels[] array without an upper size limit) without > breaking compatibility. > > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> > --- > include/hw/or-irq.h | 5 ++++- > hw/core/or-irq.c | 39 +++++++++++++++++++++++++++++++++++++-- > 2 files changed, 41 insertions(+), 3 deletions(-) > > diff --git a/include/hw/or-irq.h b/include/hw/or-irq.h > index 3f6fc1b58a4..5a31e5a1881 100644 > --- a/include/hw/or-irq.h > +++ b/include/hw/or-irq.h > @@ -31,7 +31,10 @@ > > #define TYPE_OR_IRQ "or-irq" > > -#define MAX_OR_LINES 16 > +/* This can safely be increased if necessary without breaking > + * migration compatibility (as long as it remains greater than 15). > + */ > +#define MAX_OR_LINES 32 > > typedef struct OrIRQState qemu_or_irq; > > diff --git a/hw/core/or-irq.c b/hw/core/or-irq.c > index f9d76c46415..a86901b673c 100644 > --- a/hw/core/or-irq.c > +++ b/hw/core/or-irq.c > @@ -66,14 +66,49 @@ static void or_irq_init(Object *obj) > qdev_init_gpio_out(DEVICE(obj), &s->out_irq, 1); > } > > +/* The original version of this device had a fixed 16 entries in its > + * VMState array; devices with more inputs than this need to > + * migrate the extra lines via a subsection. > + * The subsection migrates as much of the levels[] array as is needed > + * (including repeating the first 16 elements), to avoid the awkwardness > + * of splitting it in two to meet the requirements of VMSTATE_VARRAY_UINT16. > + */ > +#define OLD_MAX_OR_LINES 16 > +#if MAX_OR_LINES < OLD_MAX_OR_LINES > +#error MAX_OR_LINES must be at least 16 for migration compatibility > +#endif > + > +static bool vmstate_extras_needed(void *opaque) > +{ > + qemu_or_irq *s = OR_IRQ(opaque); > + > + return s->num_lines >= OLD_MAX_OR_LINES; > +} > + > +static const VMStateDescription vmstate_or_irq_extras = { > + .name = "or-irq-extras", > + .version_id = 1, > + .minimum_version_id = 1, > + .needed = vmstate_extras_needed, > + .fields = (VMStateField[]) { > + VMSTATE_VARRAY_UINT16_UNSAFE(levels, qemu_or_irq, num_lines, 0, > + vmstate_info_bool, bool), > + VMSTATE_END_OF_LIST(), > + }, > +}; > + > static const VMStateDescription vmstate_or_irq = { > .name = TYPE_OR_IRQ, > .version_id = 1, > .minimum_version_id = 1, > .fields = (VMStateField[]) { > - VMSTATE_BOOL_ARRAY(levels, qemu_or_irq, MAX_OR_LINES), > + VMSTATE_BOOL_SUB_ARRAY(levels, qemu_or_irq, 0, OLD_MAX_OR_LINES), > VMSTATE_END_OF_LIST(), > - } > + }, > + .subsections = (const VMStateDescription*[]) { > + &vmstate_or_irq_extras, > + NULL > + }, > }; > > static Property or_irq_properties[] = { -- Alex Bennée
diff --git a/include/hw/or-irq.h b/include/hw/or-irq.h index 3f6fc1b58a4..5a31e5a1881 100644 --- a/include/hw/or-irq.h +++ b/include/hw/or-irq.h @@ -31,7 +31,10 @@ #define TYPE_OR_IRQ "or-irq" -#define MAX_OR_LINES 16 +/* This can safely be increased if necessary without breaking + * migration compatibility (as long as it remains greater than 15). + */ +#define MAX_OR_LINES 32 typedef struct OrIRQState qemu_or_irq; diff --git a/hw/core/or-irq.c b/hw/core/or-irq.c index f9d76c46415..a86901b673c 100644 --- a/hw/core/or-irq.c +++ b/hw/core/or-irq.c @@ -66,14 +66,49 @@ static void or_irq_init(Object *obj) qdev_init_gpio_out(DEVICE(obj), &s->out_irq, 1); } +/* The original version of this device had a fixed 16 entries in its + * VMState array; devices with more inputs than this need to + * migrate the extra lines via a subsection. + * The subsection migrates as much of the levels[] array as is needed + * (including repeating the first 16 elements), to avoid the awkwardness + * of splitting it in two to meet the requirements of VMSTATE_VARRAY_UINT16. + */ +#define OLD_MAX_OR_LINES 16 +#if MAX_OR_LINES < OLD_MAX_OR_LINES +#error MAX_OR_LINES must be at least 16 for migration compatibility +#endif + +static bool vmstate_extras_needed(void *opaque) +{ + qemu_or_irq *s = OR_IRQ(opaque); + + return s->num_lines >= OLD_MAX_OR_LINES; +} + +static const VMStateDescription vmstate_or_irq_extras = { + .name = "or-irq-extras", + .version_id = 1, + .minimum_version_id = 1, + .needed = vmstate_extras_needed, + .fields = (VMStateField[]) { + VMSTATE_VARRAY_UINT16_UNSAFE(levels, qemu_or_irq, num_lines, 0, + vmstate_info_bool, bool), + VMSTATE_END_OF_LIST(), + }, +}; + static const VMStateDescription vmstate_or_irq = { .name = TYPE_OR_IRQ, .version_id = 1, .minimum_version_id = 1, .fields = (VMStateField[]) { - VMSTATE_BOOL_ARRAY(levels, qemu_or_irq, MAX_OR_LINES), + VMSTATE_BOOL_SUB_ARRAY(levels, qemu_or_irq, 0, OLD_MAX_OR_LINES), VMSTATE_END_OF_LIST(), - } + }, + .subsections = (const VMStateDescription*[]) { + &vmstate_or_irq_extras, + NULL + }, }; static Property or_irq_properties[] = {
For the IoTKit MPC support, we need to wire together the interrupt outputs of 17 MPCs; this exceeds the current value of MAX_OR_LINES. Increase MAX_OR_LINES to 32 (which should be enough for anyone). The tricky part is retaining the migration compatibility for existing OR gates; we add a subsection which is only used for larger OR gates, and define it such that we can freely increase MAX_OR_LINES in future (or even move to a dynamically allocated levels[] array without an upper size limit) without breaking compatibility. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- include/hw/or-irq.h | 5 ++++- hw/core/or-irq.c | 39 +++++++++++++++++++++++++++++++++++++-- 2 files changed, 41 insertions(+), 3 deletions(-) -- 2.17.1