On Mon, 18 Feb 2019 at 19:54, Dave Martin <Dave.Martin at arm.com> wrote: > > Since the the sizes of individual members of the core arm64 > registers vary, the list of register encodings that make sense is > not a simple linear sequence. > > To clarify which encodings to use, this patch adds a brief list > to the documentation. > > Signed-off-by: Dave Martin <Dave.Martin at arm.com> > --- > Documentation/virtual/kvm/api.txt | 24 ++++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt > index 356156f..097b8ba 100644 > --- a/Documentation/virtual/kvm/api.txt > +++ b/Documentation/virtual/kvm/api.txt > @@ -2090,6 +2090,30 @@ contains elements ranging from 32 to 128 bits. The index is a 32bit > value in the kvm_regs structure seen as a 32bit array. > 0x60x0 0000 0010 <index into the kvm_regs struct:16> > > +Specifically: > + Encoding Register Bits kvm_regs member > +---------------------------------------------------------------- > + 0x6030 0000 0010 0000 X0 64 regs.regs[0] > + 0x6030 0000 0010 0002 X1 64 regs.regs[1] > + ... > + 0x6030 0000 0010 003c X30 64 regs.regs[30] > + 0x6030 0000 0010 003e SP 64 regs.sp > + 0x6030 0000 0010 0040 PC 64 regs.pc > + 0x6030 0000 0010 0042 PSTATE 64 regs.pstate > + 0x6030 0000 0010 0044 SP_EL1 64 sp_el1 > + 0x6030 0000 0010 0046 ELR_EL1 64 elr_el1 > + 0x6030 0000 0010 0048 SPSR_EL1 64 spsr[KVM_SPSR_EL1] (alias SPSR_SVC) > + 0x6030 0000 0010 004a SPSR_ABT 64 spsr[KVM_SPSR_ABT] > + 0x6030 0000 0010 004c SPSR_UND 64 spsr[KVM_SPSR_UND] > + 0x6030 0000 0010 004e SPSR_IRQ 64 spsr[KVM_SPSR_IRQ] > + 0x6060 0000 0010 0050 SPSR_FIQ 64 spsr[KVM_SPSR_FIQ] > + 0x6040 0000 0010 0054 V0 128 fp_regs.vregs[0] > + 0x6040 0000 0010 0058 V1 128 fp_regs.vregs[1] > + ... > + 0x6040 0000 0010 00d0 V31 128 fp_regs.vregs[31] > + 0x6020 0000 0010 00d4 FPSR 32 fp_regs.fpsr > + 0x6020 0000 0010 00d5 FPCR 32 fp_regs.fpcr > + > arm64 CCSIDR registers are demultiplexed by CSSELR value: > 0x6020 0000 0011 00 <csselr:8> Reviewed-by: Peter Maydell <peter.maydell at linaro.org> It is weird that we document these in terms of apparently arbitrary hex digits in the encoding, but the headers exposed to userspace define helpful #defines for the various subfields. So nobody really wants to use these hex digits and they need to then go hunting in the headers to confirm that if they use KVM_REG_ARM64 | KVM_REG_SIZE_U32 | KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(fp_regs.fpsr) they are getting the officially approved working encoding. But it is how we're documenting everything else in this section, so that's a separate issue. thanks -- PMM
