RE: [Qemu-ppc] [RFC PATCH 12/17] PowerPC: booke64: Add DO_KVM kernel hooks
flat view
From: Caraman Mihai Claudiu-B02008 <hidden>
Date: 2012-07-04 18:15:13
Also in:
kvm
________________________________________=0A= From: Alexander Graf [agraf@suse.de]=0A= Sent: Wednesday, July 04, 2012 6:45 PM=0A= To: Caraman Mihai Claudiu-B02008=0A= Cc: <redacted>; KVM list; linuxppc-dev; qemu-ppc@nongnu.org=
List; Benjamin Herrenschmidt=0A=
Subject: Re: [Qemu-ppc] [RFC PATCH 12/17] PowerPC: booke64: Add DO_KVM ker=
nel hooks=0A=
=0A= On 04.07.2012, at 17:27, Caraman Mihai Claudiu-B02008 wrote:=0A= =0A=quoted
quoted
-----Original Message-----=0A= From: Alexander Graf [mailto:agraf@suse.de]=0A= Sent: Wednesday, July 04, 2012 5:30 PM=0A= To: Caraman Mihai Claudiu-B02008=0A= Cc: <redacted>; KVM list; linuxppc-dev; qemu-=0A= ppc@nongnu.org List; Benjamin Herrenschmidt=0A= Subject: Re: [Qemu-ppc] [RFC PATCH 12/17] PowerPC: booke64: Add DO_KVM=
=0A=
quoted
quoted
kernel hooks=0A= =0A= =0A= On 25.06.2012, at 14:26, Mihai Caraman wrote:=0A= =0A=quoted
Hook DO_KVM macro to 64-bit booke in a optimal way similar to 32-bit=
=0A=
quoted
quoted
booke=0A=quoted
see head_fsl_booke.S file. Extend interrupt handlers' parameter list=
=0A=
quoted
quoted
with=0A=quoted
interrupt vector numbers to accomodate the macro. Rework Guest Doorbel=
l=0A=
quoted
quoted
quoted
handler to use the proper GSRRx save/restore registers.=0A= Only the bolted version of tlb miss handers is addressed now.=0A= =0A= Signed-off-by: Mihai Caraman <redacted>=0A= ---=0A= arch/powerpc/kernel/exceptions-64e.S | 114 ++++++++++++++++++++++++--=
-=0A=
quoted
quoted
-------=0A=quoted
arch/powerpc/mm/tlb_low_64e.S | 14 +++-=0A= 2 files changed, 92 insertions(+), 36 deletions(-)=0A= =0A=diff --git a/arch/powerpc/kernel/exceptions-64e.S=0A=b/arch/powerpc/kernel/exceptions-64e.S=0A=quoted
index 06f7aec..a60f81f 100644=0A=--- a/arch/powerpc/kernel/exceptions-64e.S=0A= +++ b/arch/powerpc/kernel/exceptions-64e.S=0A=@@ -25,6 +25,8 @@=0A=#include <asm/ppc-opcode.h>=0A= #include <asm/mmu.h>=0A= #include <asm/hw_irq.h>=0A= +#include <asm/kvm_asm.h>=0A= +#include <asm/kvm_booke_hv_asm.h>=0A= =0A= /* XXX This will ultimately add space for a special exception save=0A= * structure used to save things like SRR0/SRR1, SPRGs, MAS, etc...=
=0A=
quoted
quoted
quoted
@@ -34,13 +36,24 @@=0A=*/=0A= #define SPECIAL_EXC_FRAME_SIZE INT_FRAME_SIZE=0A= =0A= +#ifdef CONFIG_KVM_BOOKE_HV=0A= +#define KVM_BOOKE_HV_MFSPR(reg, spr) \=
=0A=
quoted
quoted
quoted
+ BEGIN_FTR_SECTION \=0A= + mfspr reg, spr; \=0A= + END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)=0A= +#else=0A= +#define KVM_BOOKE_HV_MFSPR(reg, spr)=0A= +#endif=0A==0A= Bleks - this is ugly.=0A==0A= I agree :) But I opted to keep the optimizations done for 32-bit.=0A= =0A=quoted
Do we really need to open-code the #ifdef here?=0A==0A= 32-bit implementation fortunately use asm macros, we can't nest defines.=
=0A=
quoted
=0A=quoted
Can't the feature section code determine that the feature is disabled a=
nd=0A=
quoted
quoted
just always not include the code?=0A==0A= CPU_FTR_EMB_HV is set even if KVM is not configured.=0A==0A= I don't get the point then. Why not have the whole DO_KVM masked under FTR=
_SECTION_IFSET(CPU_FTR_EMB_HV)? Are there book3s_64 implementations without= HV? =0A= =0A= I guess you refer to book3e_64. I don't know all implementations but Embedd= ed.HV category is optional.=0A= =0A=
Can't we just mfspr unconditionally in DO_KVM?=0A=
=0A= I think Scott should better answer this question, I don't know why he opted= for the other approach.=0A= =0A=
quoted
quoted
quoted
-/* Guest Doorbell */=0A= - MASKABLE_EXCEPTION(0x2c0, guest_doorbell, .unknown_exception,=0A=ACK_NONE)=0A=quoted
+/*=0A= + * Guest doorbell interrupt=0A= + * This general exception use GSRRx save/restore registers=0A= + */=0A= + START_EXCEPTION(guest_doorbell);=0A= + EXCEPTION_PROLOG(0x2c0, BOOKE_INTERRUPT_GUEST_DBELL, GEN,=0A= + SPRN_GSRR0, SPRN_GSRR1, PROLOG_ADDITION_NONE)=0A= + EXCEPTION_COMMON(0x2c0, PACA_EXGEN, INTS_KEEP)=0A= + addi r3,r1,STACK_FRAME_OVERHEAD=0A= + bl .save_nvgprs=0A= + INTS_RESTORE_HARD=0A= + bl .unknown_exception=0A= + b .ret_from_except=0A==0A= This is independent of DO_KVM, right?=0A==0A= Yes, just kvm_handler definitions in bookehv_interrupts.S depends on thi=
s.=0A=
=0A= Then please split it out into a separate patch.=0A=
=0A= Can you be more precise, are you referring to guest_doorbell exception hand= ler?=0A= =0A=
quoted
quoted
quoted
-.macro tlb_prolog_bolted addr=0A= +.macro tlb_prolog_bolted intnum addr=0A= mtspr SPRN_SPRG_TLB_SCRATCH,r13=0A= mfspr r13,SPRN_SPRG_PACA=0A= std r10,PACA_EXTLB+EX_TLB_R10(r13)=0A= mfcr r10=0A= std r11,PACA_EXTLB+EX_TLB_R11(r13)=0A= +#ifdef CONFIG_KVM_BOOKE_HV=0A= +BEGIN_FTR_SECTION=0A= + mfspr r11, SPRN_SRR1=0A= +END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)=0A= +#endif=0A==0A= This thing really should vanish behind DO_KVM :)=0A==0A= Then let's do it first for 32-bit ;)=0A==0A= You could #ifdef it in DO_KVM for 64-bit for now. IIRC it's not done on 32=
-bit because the register value is used even beyond DO_KVM there.=0A= =0A= Nope, 32-bit code is also guarded by CONFIG_KVM_BOOKE_HV.=0A= =0A= -Mike=