On 03/02/17 14:00, Peter Maydell wrote: > On 12 January 2017 at 15:56, Eric Auger <eric.auger@xxxxxxxxxx> wrote: >> Add description for how to access vITS registers and how to flush/restore >> vITS tables into/from memory >> >> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx> >> --- >> Documentation/virtual/kvm/devices/arm-vgic-its.txt | 70 ++++++++++++++++++++++ >> 1 file changed, 70 insertions(+) >> >> diff --git a/Documentation/virtual/kvm/devices/arm-vgic-its.txt b/Documentation/virtual/kvm/devices/arm-vgic-its.txt >> index 6081a5b..bd74613 100644 >> --- a/Documentation/virtual/kvm/devices/arm-vgic-its.txt >> +++ b/Documentation/virtual/kvm/devices/arm-vgic-its.txt >> @@ -36,3 +36,73 @@ Groups: >> -ENXIO: ITS not properly configured as required prior to setting >> this attribute >> -ENOMEM: Memory shortage when allocating ITS internal data >> + >> + KVM_DEV_ARM_VGIC_GRP_ITS_REGS >> + Attributes: >> + The attr field of kvm_device_attr encodes the offset of the >> + ITS register, relative to the ITS control frame base address >> + (ITS_base). >> + >> + kvm_device_attr.addr points to a __u64 value whatever the width >> + of the addressed register (32/64 bits). >> + >> + Writes to read-only registers are ignored by the kernel except >> + for a single register, GITS_READR. Normally this register is RO >> + but it needs to be restored otherwise commands in the queue will >> + be re-executed after CWRITER setting. > > Dumb question -- is it possible/sensible to process the command > queue rather than migrating a list of outstanding commands? It is not always possible, specially if the ITS implements the "stall" mechanism, where it waits for SW acknowledgement in case of a command error. Thanks, M. -- Jazz is not dead. It just smells funny...
