| Message ID | 1302881578-5357-11-git-send-email-agraf@suse.de |
|---|---|
| State | New |
| Headers | show |
On Fri, Apr 15, 2011 at 05:32:51PM +0200, Alexander Graf wrote: > The s390x virtio bus keeps management information on virtio after the top > of the guest's RAM. We need to be able to tell the guest the size of its > RAM (without virtio stuff), but also be able to trap when the guest accesses > RAM outside of its scope (including virtio stuff). > > So we need a variable telling us the size of the virtio stuff, so we can > calculate the highest available RAM address from that. > > While at it, also increase the maximum number of virtio pages, so we play > along well with more recent kernels that spawn a ridiculous number of virtio > console adapters. > > Signed-off-by: Alexander Graf <agraf@suse.de> > --- > hw/s390-virtio-bus.c | 3 +++ > hw/s390-virtio-bus.h | 2 +- > target-s390x/cpu.h | 3 +++ > 3 files changed, 7 insertions(+), 1 deletions(-) > > diff --git a/hw/s390-virtio-bus.c b/hw/s390-virtio-bus.c > index bb49e39..a90963b 100644 > --- a/hw/s390-virtio-bus.c > +++ b/hw/s390-virtio-bus.c > @@ -60,6 +60,9 @@ static const VirtIOBindings virtio_s390_bindings; > > static ram_addr_t s390_virtio_device_num_vq(VirtIOS390Device *dev); > > +/* length of VirtIO device pages */ > +target_phys_addr_t virtio_size = S390_DEVICE_PAGES * TARGET_PAGE_SIZE; > + If this variable is never written, can it be declared const? > VirtIOS390Bus *s390_virtio_bus_init(ram_addr_t *ram_size) > { > VirtIOS390Bus *bus; > diff --git a/hw/s390-virtio-bus.h b/hw/s390-virtio-bus.h > index edf6d04..0c412d0 100644 > --- a/hw/s390-virtio-bus.h > +++ b/hw/s390-virtio-bus.h > @@ -33,7 +33,7 @@ > #define VIRTIO_VQCONFIG_LEN 24 > > #define VIRTIO_RING_LEN (TARGET_PAGE_SIZE * 3) > -#define S390_DEVICE_PAGES 256 > +#define S390_DEVICE_PAGES 512 > > typedef struct VirtIOS390Device { > DeviceState qdev; > diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h > index a84b3ee..6ba303d 100644 > --- a/target-s390x/cpu.h > +++ b/target-s390x/cpu.h > @@ -293,6 +293,9 @@ void kvm_s390_interrupt_internal(CPUState *env, int type, uint32_t parm, > uint64_t parm64, int vm); > CPUState *s390_cpu_addr2state(uint16_t cpu_addr); > > +/* from s390-virtio-bus */ > +extern target_phys_addr_t virtio_size; > + > #ifndef KVM_S390_SIGP_STOP > #define KVM_S390_SIGP_STOP 0 > #define KVM_S390_PROGRAM_INT 0
On 18.04.2011, at 21:06, Aurelien Jarno wrote: > On Fri, Apr 15, 2011 at 05:32:51PM +0200, Alexander Graf wrote: >> The s390x virtio bus keeps management information on virtio after the top >> of the guest's RAM. We need to be able to tell the guest the size of its >> RAM (without virtio stuff), but also be able to trap when the guest accesses >> RAM outside of its scope (including virtio stuff). >> >> So we need a variable telling us the size of the virtio stuff, so we can >> calculate the highest available RAM address from that. >> >> While at it, also increase the maximum number of virtio pages, so we play >> along well with more recent kernels that spawn a ridiculous number of virtio >> console adapters. >> >> Signed-off-by: Alexander Graf <agraf@suse.de> >> --- >> hw/s390-virtio-bus.c | 3 +++ >> hw/s390-virtio-bus.h | 2 +- >> target-s390x/cpu.h | 3 +++ >> 3 files changed, 7 insertions(+), 1 deletions(-) >> >> diff --git a/hw/s390-virtio-bus.c b/hw/s390-virtio-bus.c >> index bb49e39..a90963b 100644 >> --- a/hw/s390-virtio-bus.c >> +++ b/hw/s390-virtio-bus.c >> @@ -60,6 +60,9 @@ static const VirtIOBindings virtio_s390_bindings; >> >> static ram_addr_t s390_virtio_device_num_vq(VirtIOS390Device *dev); >> >> +/* length of VirtIO device pages */ >> +target_phys_addr_t virtio_size = S390_DEVICE_PAGES * TARGET_PAGE_SIZE; >> + > > If this variable is never written, can it be declared const? Does that improve anything for exported variables? Do they get put into a ro section then? Alex
On Mon, Apr 18, 2011 at 11:03:59PM +0200, Alexander Graf wrote: > > On 18.04.2011, at 21:06, Aurelien Jarno wrote: > > > On Fri, Apr 15, 2011 at 05:32:51PM +0200, Alexander Graf wrote: > >> The s390x virtio bus keeps management information on virtio after the top > >> of the guest's RAM. We need to be able to tell the guest the size of its > >> RAM (without virtio stuff), but also be able to trap when the guest accesses > >> RAM outside of its scope (including virtio stuff). > >> > >> So we need a variable telling us the size of the virtio stuff, so we can > >> calculate the highest available RAM address from that. > >> > >> While at it, also increase the maximum number of virtio pages, so we play > >> along well with more recent kernels that spawn a ridiculous number of virtio > >> console adapters. > >> > >> Signed-off-by: Alexander Graf <agraf@suse.de> > >> --- > >> hw/s390-virtio-bus.c | 3 +++ > >> hw/s390-virtio-bus.h | 2 +- > >> target-s390x/cpu.h | 3 +++ > >> 3 files changed, 7 insertions(+), 1 deletions(-) > >> > >> diff --git a/hw/s390-virtio-bus.c b/hw/s390-virtio-bus.c > >> index bb49e39..a90963b 100644 > >> --- a/hw/s390-virtio-bus.c > >> +++ b/hw/s390-virtio-bus.c > >> @@ -60,6 +60,9 @@ static const VirtIOBindings virtio_s390_bindings; > >> > >> static ram_addr_t s390_virtio_device_num_vq(VirtIOS390Device *dev); > >> > >> +/* length of VirtIO device pages */ > >> +target_phys_addr_t virtio_size = S390_DEVICE_PAGES * TARGET_PAGE_SIZE; > >> + > > > > If this variable is never written, can it be declared const? > > Does that improve anything for exported variables? Do they get put into a ro section then? > Unfortunately, that will still be an exported variable, and it's a pitty to use that just because we can't have a #define in hw/* included in target-*/* . That said I just realized that a lot of target are actually doing that, maybe it's the solution here. Adding a const here will clearly show to people reading the code that it's nothing more than advanced #define.
diff --git a/hw/s390-virtio-bus.c b/hw/s390-virtio-bus.c index bb49e39..a90963b 100644 --- a/hw/s390-virtio-bus.c +++ b/hw/s390-virtio-bus.c @@ -60,6 +60,9 @@ static const VirtIOBindings virtio_s390_bindings; static ram_addr_t s390_virtio_device_num_vq(VirtIOS390Device *dev); +/* length of VirtIO device pages */ +target_phys_addr_t virtio_size = S390_DEVICE_PAGES * TARGET_PAGE_SIZE; + VirtIOS390Bus *s390_virtio_bus_init(ram_addr_t *ram_size) { VirtIOS390Bus *bus; diff --git a/hw/s390-virtio-bus.h b/hw/s390-virtio-bus.h index edf6d04..0c412d0 100644 --- a/hw/s390-virtio-bus.h +++ b/hw/s390-virtio-bus.h @@ -33,7 +33,7 @@ #define VIRTIO_VQCONFIG_LEN 24 #define VIRTIO_RING_LEN (TARGET_PAGE_SIZE * 3) -#define S390_DEVICE_PAGES 256 +#define S390_DEVICE_PAGES 512 typedef struct VirtIOS390Device { DeviceState qdev; diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h index a84b3ee..6ba303d 100644 --- a/target-s390x/cpu.h +++ b/target-s390x/cpu.h @@ -293,6 +293,9 @@ void kvm_s390_interrupt_internal(CPUState *env, int type, uint32_t parm, uint64_t parm64, int vm); CPUState *s390_cpu_addr2state(uint16_t cpu_addr); +/* from s390-virtio-bus */ +extern target_phys_addr_t virtio_size; + #ifndef KVM_S390_SIGP_STOP #define KVM_S390_SIGP_STOP 0 #define KVM_S390_PROGRAM_INT 0
The s390x virtio bus keeps management information on virtio after the top of the guest's RAM. We need to be able to tell the guest the size of its RAM (without virtio stuff), but also be able to trap when the guest accesses RAM outside of its scope (including virtio stuff). So we need a variable telling us the size of the virtio stuff, so we can calculate the highest available RAM address from that. While at it, also increase the maximum number of virtio pages, so we play along well with more recent kernels that spawn a ridiculous number of virtio console adapters. Signed-off-by: Alexander Graf <agraf@suse.de> --- hw/s390-virtio-bus.c | 3 +++ hw/s390-virtio-bus.h | 2 +- target-s390x/cpu.h | 3 +++ 3 files changed, 7 insertions(+), 1 deletions(-)