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MIPS: KVM: Expose FPU registers

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Add KVM register numbers for the MIPS FPU registers, and implement
access to them with the KVM_GET_ONE_REG / KVM_SET_ONE_REG ioctls when
the FPU capability is enabled (exposed in a later patch) and present in
the guest according to its Config1.FP bit.

The registers are accessible in the current mode of the guest, with each
sized access showing what the guest would see with an equivalent access,
and like the architecture they may become UNPREDICTABLE if the FR mode
is changed. When FR=0, odd doubles are inaccessible as they do not exist
in that mode.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: linux-api@vger.kernel.org
Cc: linux-doc@vger.kernel.org
This commit is contained in:
James Hogan
2014-12-02 15:48:24 +00:00
parent 1c0cd66adb
commit 379245cdf1
3 changed files with 114 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
Documentation/virtual/kvm/api.txt
View File

@@ -1979,6 +1979,10 @@ registers, find a list below:
MIPS | KVM_REG_MIPS_COUNT_CTL | 64
MIPS | KVM_REG_MIPS_COUNT_RESUME | 64
MIPS | KVM_REG_MIPS_COUNT_HZ | 64
MIPS | KVM_REG_MIPS_FPR_32(0..31) | 32
MIPS | KVM_REG_MIPS_FPR_64(0..31) | 64
MIPS | KVM_REG_MIPS_FCR_IR | 32
MIPS | KVM_REG_MIPS_FCR_CSR | 32
ARM registers are mapped using the lower 32 bits. The upper 16 of that
is the register group type, or coprocessor number:
@@ -2032,6 +2036,18 @@ patterns depending on whether they're 32-bit or 64-bit registers:
MIPS KVM control registers (see above) have the following id bit patterns:
0x7030 0000 0002 <reg:16>
MIPS FPU registers (see KVM_REG_MIPS_FPR_{32,64}() above) have the following
id bit patterns depending on the size of the register being accessed. They are
always accessed according to the current guest FPU mode (Status.FR and
Config5.FRE), i.e. as the guest would see them, and they become unpredictable
if the guest FPU mode is changed:
0x7020 0000 0003 00 <0:3> <reg:5> (32-bit FPU registers)
0x7030 0000 0003 00 <0:3> <reg:5> (64-bit FPU registers)
MIPS FPU control registers (see KVM_REG_MIPS_FCR_{IR,CSR} above) have the
following id bit patterns:
0x7020 0000 0003 01 <0:3> <reg:5>
4.69 KVM_GET_ONE_REG