On 28.02.2013, at 05:13, Bharat Bhushan wrote: > On Guest entry: if guest is wants to use the debug register then > save h/w debug register in host_dbg_reg and load the debug registers > with shadow_dbg_reg. Otherwise leave h/w debug registers as is.
Why can't we switch the majority of registers on vcpu_put/get and only enable or disable debugging on guest entry/exit? Alex > > On guest exit: If guest/user-space is using the debug resource then > restore the h/w debug register with host_dbg_reg. No need to save guest > debug register as shadow_dbg_reg is having required values. If guest is not > using the debug resources then no need to restore h/w registers. > > Signed-off-by: Bharat Bhushan <[email protected]> > --- > arch/powerpc/include/asm/kvm_host.h | 5 ++ > arch/powerpc/kernel/asm-offsets.c | 26 ++++++++ > arch/powerpc/kvm/booke_interrupts.S | 114 +++++++++++++++++++++++++++++++++++ > 3 files changed, 145 insertions(+), 0 deletions(-) > > diff --git a/arch/powerpc/include/asm/kvm_host.h > b/arch/powerpc/include/asm/kvm_host.h > index f4ba881..a9feeb0 100644 > --- a/arch/powerpc/include/asm/kvm_host.h > +++ b/arch/powerpc/include/asm/kvm_host.h > @@ -504,7 +504,12 @@ struct kvm_vcpu_arch { > u32 mmucfg; > u32 epr; > u32 crit_save; > + /* guest debug registers*/ > struct kvmppc_booke_debug_reg dbg_reg; > + /* shadow debug registers */ > + struct kvmppc_booke_debug_reg shadow_dbg_reg; > + /* host debug registers*/ > + struct kvmppc_booke_debug_reg host_dbg_reg; > #endif > gpa_t paddr_accessed; > gva_t vaddr_accessed; > diff --git a/arch/powerpc/kernel/asm-offsets.c > b/arch/powerpc/kernel/asm-offsets.c > index 02048f3..22deda7 100644 > --- a/arch/powerpc/kernel/asm-offsets.c > +++ b/arch/powerpc/kernel/asm-offsets.c > @@ -563,6 +563,32 @@ int main(void) > DEFINE(VCPU_FAULT_DEAR, offsetof(struct kvm_vcpu, arch.fault_dear)); > DEFINE(VCPU_FAULT_ESR, offsetof(struct kvm_vcpu, arch.fault_esr)); > DEFINE(VCPU_CRIT_SAVE, offsetof(struct kvm_vcpu, arch.crit_save)); > + DEFINE(VCPU_DBSR, offsetof(struct kvm_vcpu, arch.dbsr)); > + DEFINE(VCPU_SHADOW_DBG, offsetof(struct kvm_vcpu, arch.shadow_dbg_reg)); > + DEFINE(VCPU_HOST_DBG, offsetof(struct kvm_vcpu, arch.host_dbg_reg)); > + DEFINE(KVMPPC_DBG_DBCR0, offsetof(struct kvmppc_booke_debug_reg, > + dbcr0)); > + DEFINE(KVMPPC_DBG_DBCR1, offsetof(struct kvmppc_booke_debug_reg, > + dbcr1)); > + DEFINE(KVMPPC_DBG_DBCR2, offsetof(struct kvmppc_booke_debug_reg, > + dbcr2)); > +#ifdef CONFIG_KVM_E500MC > + DEFINE(KVMPPC_DBG_DBCR4, offsetof(struct kvmppc_booke_debug_reg, > + dbcr4)); > +#endif > + DEFINE(KVMPPC_DBG_IAC1, offsetof(struct kvmppc_booke_debug_reg, > + iac[0])); > + DEFINE(KVMPPC_DBG_IAC2, offsetof(struct kvmppc_booke_debug_reg, > + iac[1])); > + DEFINE(KVMPPC_DBG_IAC3, offsetof(struct kvmppc_booke_debug_reg, > + iac[2])); > + DEFINE(KVMPPC_DBG_IAC4, offsetof(struct kvmppc_booke_debug_reg, > + iac[3])); > + DEFINE(KVMPPC_DBG_DAC1, offsetof(struct kvmppc_booke_debug_reg, > + dac[0])); > + DEFINE(KVMPPC_DBG_DAC2, offsetof(struct kvmppc_booke_debug_reg, > + dac[1])); > + DEFINE(VCPU_GUEST_DEBUG, offsetof(struct kvm_vcpu, guest_debug)); > #endif /* CONFIG_PPC_BOOK3S */ > #endif /* CONFIG_KVM */ > > diff --git a/arch/powerpc/kvm/booke_interrupts.S > b/arch/powerpc/kvm/booke_interrupts.S > index 2c6deb5..6d78e01 100644 > --- a/arch/powerpc/kvm/booke_interrupts.S > +++ b/arch/powerpc/kvm/booke_interrupts.S > @@ -39,6 +39,8 @@ > #define HOST_MIN_STACK_SIZE (HOST_NV_GPR(R31) + 4) > #define HOST_STACK_SIZE (((HOST_MIN_STACK_SIZE + 15) / 16) * 16) /* Align. */ > #define HOST_STACK_LR (HOST_STACK_SIZE + 4) /* In caller stack frame. */ > +#define DBCR0_AC_BITS (DBCR0_IAC1 | DBCR0_IAC2 | DBCR0_IAC3 | > DBCR0_IAC4 | \ > + DBCR0_DAC1R | DBCR0_DAC1W | DBCR0_DAC2R | DBCR0_DAC2W) > > #define NEED_INST_MASK ((1<<BOOKE_INTERRUPT_PROGRAM) | \ > (1<<BOOKE_INTERRUPT_DTLB_MISS) | \ > @@ -54,6 +56,8 @@ > (1<<BOOKE_INTERRUPT_DTLB_MISS) | \ > (1<<BOOKE_INTERRUPT_ALIGNMENT)) > > +#define NEED_DEBUG_SAVE (1<<BOOKE_INTERRUPT_DEBUG) > + > .macro __KVM_HANDLER ivor_nr scratch srr0 > /* Get pointer to vcpu and record exit number. */ > mtspr \scratch , r4 > @@ -215,6 +219,59 @@ _GLOBAL(kvmppc_resume_host) > stw r9, VCPU_FAULT_ESR(r4) > ..skip_esr: > > + lwz r9, VCPU_SHADOW_DBG+KVMPPC_DBG_DBCR0(r4) > + rlwinm. r8, r9, 0, ~DBCR0_IDM > + beq skip_load_host_debug > + lwz r8, VCPU_HOST_DBG+KVMPPC_DBG_DBCR0(r4) > + andis. r9, r9, DBCR0_AC_BITS@h > + li r9, 0 > + mtspr SPRN_DBCR0, r9 /* disable all debug event */ > + beq skip_load_hw_bkpts > + lwz r7, VCPU_HOST_DBG+KVMPPC_DBG_DBCR1(r4) > + lwz r9, VCPU_HOST_DBG+KVMPPC_DBG_DBCR2(r4) > + mtspr SPRN_DBCR1, r7 > + mtspr SPRN_DBCR2, r9 > + PPC_LD(r7, VCPU_HOST_DBG+KVMPPC_DBG_IAC1, r4) > + PPC_LD(r9, VCPU_HOST_DBG+KVMPPC_DBG_IAC2, r4) > + mtspr SPRN_IAC1, r7 > + mtspr SPRN_IAC2, r9 > +#if CONFIG_PPC_ADV_DEBUG_IACS > 2 > + PPC_LD(r7, VCPU_HOST_DBG+KVMPPC_DBG_IAC3, r4) > + PPC_LD(r9, VCPU_HOST_DBG+KVMPPC_DBG_IAC4, r4) > + mtspr SPRN_IAC3, r3 > + mtspr SPRN_IAC4, r4 > +#endif > + PPC_LD(r7, VCPU_HOST_DBG+KVMPPC_DBG_DAC1, r4) > + PPC_LD(r9, VCPU_HOST_DBG+KVMPPC_DBG_DAC2, r4) > + mtspr SPRN_DAC1, r7 > + mtspr SPRN_DAC2, r9 > +skip_load_hw_bkpts: > + /* Clear h/w DBSR and save current(guest) DBSR */ > + mfspr r9, SPRN_DBSR > + mtspr SPRN_DBSR, r9 > + isync > + andi. r7, r6, NEED_DEBUG_SAVE > + beq skip_dbsr_save > + /* > + * If vcpu->guest_debug flag is set then do not check for > + * shared->msr.DE as this debugging (say by QEMU) does not > + * depends on shared->msr.de. In these scanerios MSR.DE is > + * always set using shared_msr and should be handled always. > + */ > + lwz r7, VCPU_GUEST_DEBUG(r4) > + cmpwi r7, 0 > + bne skip_save_trap_event > + PPC_LL r3, VCPU_SHARED(r4) > + PPC_LD(r3, VCPU_SHARED_MSR, r3) > + andi. r3, r3, MSR_DE > + bne skip_save_trap_event > + andis. r9, r9, DBSR_TIE@h > +skip_save_trap_event: > + stw r9, VCPU_DBSR(r4) > +skip_dbsr_save: > + mtspr SPRN_DBCR0, r8 > +skip_load_host_debug: > + > /* Save remaining volatile guest register state to vcpu. */ > stw r0, VCPU_GPR(R0)(r4) > stw r1, VCPU_GPR(R1)(r4) > @@ -468,6 +525,63 @@ lightweight_exit: > PPC_LD(r3, VCPU_SHARED_SPRG7, r5) > mtspr SPRN_SPRG7W, r3 > > + mfmsr r7 > + rlwinm r7, r7, 0, ~MSR_DE > + mtmsr r7 > + lwz r6, VCPU_SHADOW_DBG+KVMPPC_DBG_DBCR0(r4) > + rlwinm. r7, r6, 0, ~DBCR0_IDM > + beq skip_load_guest_debug > + mfspr r8, SPRN_DBCR0 > + stw r8, VCPU_HOST_DBG+KVMPPC_DBG_DBCR0(r4) > + andis. r3, r6, DBCR0_AC_BITS@h > + beq skip_hw_bkpts > + mfspr r7, SPRN_DBCR1 > + stw r7, VCPU_HOST_DBG+KVMPPC_DBG_DBCR1(r4) > + mfspr r8, SPRN_DBCR2 > + stw r8, VCPU_HOST_DBG+KVMPPC_DBG_DBCR2(r4) > + mfspr r7, SPRN_IAC1 > + PPC_STD(r7, VCPU_HOST_DBG+KVMPPC_DBG_IAC1, r4) > + mfspr r8, SPRN_IAC2 > + PPC_STD(r8, VCPU_HOST_DBG+KVMPPC_DBG_IAC2, r4) > +#if CONFIG_PPC_ADV_DEBUG_IACS > 2 > + mfspr r7, SPRN_IAC3 > + PPC_STD(r7, VCPU_HOST_DBG+KVMPPC_DBG_IAC3, r4) > + mfspr r8, SPRN_IAC4 > + PPC_STD(r8, VCPU_HOST_DBG+KVMPPC_DBG_IAC4, r4) > +#endif > + mfspr r7, SPRN_DAC1 > + PPC_STD(r7, VCPU_HOST_DBG+KVMPPC_DBG_DAC1, r4) > + mfspr r8, SPRN_DAC2 > + PPC_STD(r8, VCPU_HOST_DBG+KVMPPC_DBG_DAC2, r4) > + li r8, 0 > + mtspr SPRN_DBCR0, r8 /* disable all debug event */ > + PPC_LD(r7, VCPU_SHADOW_DBG+KVMPPC_DBG_DBCR1, r4) > + PPC_LD(r8, VCPU_SHADOW_DBG+KVMPPC_DBG_DBCR2, r4) > + mtspr SPRN_DBCR1, r7 > + mtspr SPRN_DBCR2, r8 > + PPC_LD(r7, VCPU_SHADOW_DBG+KVMPPC_DBG_IAC1, r4) > + PPC_LD(r8, VCPU_SHADOW_DBG+KVMPPC_DBG_IAC2, r4) > + mtspr SPRN_IAC1, r7 > + mtspr SPRN_IAC2, r8 > +#if CONFIG_PPC_ADV_DEBUG_IACS > 2 > + PPC_LD(r7, VCPU_SHADOW_DBG+KVMPPC_DBG_IAC3, r4) > + PPC_LD(r8, VCPU_SHADOW_DBG+KVMPPC_DBG_IAC4, r4) > + mtspr SPRN_IAC3, r7 > + mtspr SPRN_IAC4, r8 > +#endif > + PPC_LD(r7, VCPU_SHADOW_DBG+KVMPPC_DBG_DAC1, r4) > + PPC_LD(r8, VCPU_SHADOW_DBG+KVMPPC_DBG_DAC2, r4) > + mtspr SPRN_DAC1, r7 > + mtspr SPRN_DAC2, r8 > +skip_hw_bkpts: > + /* Clear if any deferred debug event */ > + mfspr r8, SPRN_DBSR > + mtspr SPRN_DBSR, r8 > + isync > + /* Restore guest DBCR */ > + mtspr SPRN_DBCR0, r6 > +skip_load_guest_debug: > + > #ifdef CONFIG_KVM_EXIT_TIMING > /* save enter time */ > 1: > -- > 1.7.0.4 > > > -- > To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
