Re: [PATCH] KVM: PPC: remove mmio_vsx_tx_sx_enabled in PR KVM MMIO emulation

[Simon Guo]

On Thu, May 24, 2018 at 05:01:26PM +0800, wei.guo.si...@gmail.com wrote:
> From: Simon Guo 
> 
> Originally PR KVM MMIO emulation uses only 0~31#(5 bits) for VSR
> reg number, and use mmio_vsx_tx_sx_enabled field together for
> 0~63# VSR regs.
> 
> Currently PR KVM MMIO emulation is reimplemented with analyse_instr()
> assistence. analyse_instr() returns 0~63 for VSR register number, so
> it is not necessary to use additional mmio_vsx_tx_sx_enabled field
> any more.
> 
> This patch extends related reg bits(expand io_gpr to u16 from u8
> and use 6 bits for VSR reg#), so that mmio_vsx_tx_sx_enabled can
> be removed.
> 
> Signed-off-by: Simon Guo 

It applies to HV KVM too. I will correct the commit message in next 
version.

Thanks,
- Simon

[PATCH] KVM: PPC: remove mmio_vsx_tx_sx_enabled in PR KVM MMIO emulation

[wei . guo . simon]

From: Simon Guo 

Originally PR KVM MMIO emulation uses only 0~31#(5 bits) for VSR
reg number, and use mmio_vsx_tx_sx_enabled field together for
0~63# VSR regs.

Currently PR KVM MMIO emulation is reimplemented with analyse_instr()
assistence. analyse_instr() returns 0~63 for VSR register number, so
it is not necessary to use additional mmio_vsx_tx_sx_enabled field
any more.

This patch extends related reg bits(expand io_gpr to u16 from u8
and use 6 bits for VSR reg#), so that mmio_vsx_tx_sx_enabled can
be removed.

Signed-off-by: Simon Guo 
---
 arch/powerpc/include/asm/kvm_host.h  | 17 -
 arch/powerpc/kvm/emulate_loadstore.c |  7 +++
 arch/powerpc/kvm/powerpc.c   | 30 +++---
 3 files changed, 26 insertions(+), 28 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_host.h 
b/arch/powerpc/include/asm/kvm_host.h
index 8dc5e43..bd220a3 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -673,7 +673,7 @@ struct kvm_vcpu_arch {
gva_t vaddr_accessed;
pgd_t *pgdir;
 
-   u8 io_gpr; /* GPR used as IO source/target */
+   u16 io_gpr; /* GPR used as IO source/target */
u8 mmio_host_swabbed;
u8 mmio_sign_extend;
/* conversion between single and double precision */
@@ -689,7 +689,6 @@ struct kvm_vcpu_arch {
 */
u8 mmio_vsx_copy_nums;
u8 mmio_vsx_offset;
-   u8 mmio_vsx_tx_sx_enabled;
u8 mmio_vmx_copy_nums;
u8 mmio_vmx_offset;
u8 mmio_copy_type;
@@ -802,14 +801,14 @@ struct kvm_vcpu_arch {
 #define KVMPPC_VCPU_BUSY_IN_HOST   2
 
 /* Values for vcpu->arch.io_gpr */
-#define KVM_MMIO_REG_MASK  0x001f
-#define KVM_MMIO_REG_EXT_MASK  0xffe0
+#define KVM_MMIO_REG_MASK  0x003f
+#define KVM_MMIO_REG_EXT_MASK  0xffc0
 #define KVM_MMIO_REG_GPR   0x
-#define KVM_MMIO_REG_FPR   0x0020
-#define KVM_MMIO_REG_QPR   0x0040
-#define KVM_MMIO_REG_FQPR  0x0060
-#define KVM_MMIO_REG_VSX   0x0080
-#define KVM_MMIO_REG_VMX   0x00c0
+#define KVM_MMIO_REG_FPR   0x0040
+#define KVM_MMIO_REG_QPR   0x0080
+#define KVM_MMIO_REG_FQPR  0x00c0
+#define KVM_MMIO_REG_VSX   0x0100
+#define KVM_MMIO_REG_VMX   0x0180
 
 #define __KVM_HAVE_ARCH_WQP
 #define __KVM_HAVE_CREATE_DEVICE
diff --git a/arch/powerpc/kvm/emulate_loadstore.c 
b/arch/powerpc/kvm/emulate_loadstore.c
index dca7f1c..64b325b 100644
--- a/arch/powerpc/kvm/emulate_loadstore.c
+++ b/arch/powerpc/kvm/emulate_loadstore.c
@@ -106,7 +106,6 @@ int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu)
 * if mmio_vsx_tx_sx_enabled == 1, copy data between
 * VSR[32..63] and memory
 */
-   vcpu->arch.mmio_vsx_tx_sx_enabled = get_tx_or_sx(inst);
vcpu->arch.mmio_vsx_copy_nums = 0;
vcpu->arch.mmio_vsx_offset = 0;
vcpu->arch.mmio_copy_type = KVMPPC_VSX_COPY_NONE;
@@ -242,8 +241,8 @@ int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu)
}
 
emulated = kvmppc_handle_vsx_load(run, vcpu,
-   KVM_MMIO_REG_VSX | (op.reg & 0x1f),
-   io_size_each, 1, op.type & SIGNEXT);
+   KVM_MMIO_REG_VSX|op.reg, io_size_each,
+   1, op.type & SIGNEXT);
break;
}
 #endif
@@ -363,7 +362,7 @@ int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu)
}
 
emulated = kvmppc_handle_vsx_store(run, vcpu,
-   op.reg & 0x1f, io_size_each, 1);
+   op.reg, io_size_each, 1);
break;
}
 #endif
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 05eccdc..dcc7982 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -881,10 +881,10 @@ static inline void kvmppc_set_vsr_dword(struct kvm_vcpu 
*vcpu,
if (offset == -1)
return;
 
-   if (vcpu->arch.mmio_vsx_tx_sx_enabled) {
-   val.vval = VCPU_VSX_VR(vcpu, index);
+   if (index >= 32) {
+   val.vval = VCPU_VSX_VR(vcpu, index - 32);
val.vsxval[offset] = gpr;
-   VCPU_VSX_VR(vcpu, index) = val.vval;
+   VCPU_VSX_VR(vcpu, index - 32) = val.vval;
} else {
VCPU_VSX_FPR(vcpu, index, offset) = gpr;
}
@@ -896,11 +896,11 @@ static inline void kvmppc_set_vsr_dword_dump(struct 
kvm_vcpu *vcpu,
union kvmppc_one_reg val;
int index = vcpu->arch.io_gpr & KVM_MMIO_REG_MASK;
 
-   if (vcpu->arch.mmio_vsx_tx_sx_enabled) {
-   val.vval = VCPU_VSX_VR(vcpu, index);
+   if (index >= 32) {
+   val.vval = VCPU_VSX_VR(vcpu, index - 32);
val.vsxval[0] = gpr;