| Message ID | 1550568271-5319-3-git-send-email-amit.kachhap@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add ARMv8.3 pointer authentication for kvm guest | expand |
On Tue, Feb 19, 2019 at 02:54:27PM +0530, Amit Daniel Kachhap wrote: > Save host MDCR_EL2 value during kvm HYP initialisation and restore > after every switch from host to guest. There should not be any > change in functionality due to this. > > The value of mdcr_el2 is now stored in struct kvm_cpu_context as > both host and guest can now use this field in a common way. > > Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> > Cc: Marc Zyngier <marc.zyngier@arm.com> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: Christoffer Dall <christoffer.dall@arm.com> > Cc: kvmarm@lists.cs.columbia.edu > --- > arch/arm/include/asm/kvm_host.h | 1 - > arch/arm64/include/asm/kvm_host.h | 6 ++---- > arch/arm64/kvm/debug.c | 28 ++++++---------------------- > arch/arm64/kvm/hyp/switch.c | 17 ++++------------- > arch/arm64/kvm/hyp/sysreg-sr.c | 6 ++++++ > virt/kvm/arm/arm.c | 1 - > 6 files changed, 18 insertions(+), 41 deletions(-) This looks like a nice cleanup! FWIW: Acked-by: Mark Rutland <mark.rutland@arm.com> Thanks, Mark. > > diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h > index 05706b4..704667e 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -294,7 +294,6 @@ static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} > static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} > static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} > > -static inline void kvm_arm_init_debug(void) {} > static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {} > static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {} > static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {} > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index 1b2e05b..2f1bb86 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -205,6 +205,8 @@ struct kvm_cpu_context { > > /* HYP host/guest configuration */ > u64 hcr_el2; > + u32 mdcr_el2; > + > struct kvm_vcpu *__hyp_running_vcpu; > }; > > @@ -213,9 +215,6 @@ typedef struct kvm_cpu_context kvm_cpu_context_t; > struct kvm_vcpu_arch { > struct kvm_cpu_context ctxt; > > - /* HYP configuration */ > - u32 mdcr_el2; > - > /* Exception Information */ > struct kvm_vcpu_fault_info fault; > > @@ -446,7 +445,6 @@ static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} > static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} > static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} > > -void kvm_arm_init_debug(void); > void kvm_arm_setup_debug(struct kvm_vcpu *vcpu); > void kvm_arm_clear_debug(struct kvm_vcpu *vcpu); > void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu); > diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c > index f39801e..99dc0a4 100644 > --- a/arch/arm64/kvm/debug.c > +++ b/arch/arm64/kvm/debug.c > @@ -32,8 +32,6 @@ > DBG_MDSCR_KDE | \ > DBG_MDSCR_MDE) > > -static DEFINE_PER_CPU(u32, mdcr_el2); > - > /** > * save/restore_guest_debug_regs > * > @@ -65,21 +63,6 @@ static void restore_guest_debug_regs(struct kvm_vcpu *vcpu) > } > > /** > - * kvm_arm_init_debug - grab what we need for debug > - * > - * Currently the sole task of this function is to retrieve the initial > - * value of mdcr_el2 so we can preserve MDCR_EL2.HPMN which has > - * presumably been set-up by some knowledgeable bootcode. > - * > - * It is called once per-cpu during CPU hyp initialisation. > - */ > - > -void kvm_arm_init_debug(void) > -{ > - __this_cpu_write(mdcr_el2, kvm_call_hyp(__kvm_get_mdcr_el2)); > -} > - > -/** > * kvm_arm_reset_debug_ptr - reset the debug ptr to point to the vcpu state > */ > > @@ -111,6 +94,7 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) > > void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) > { > + kvm_cpu_context_t *host_cxt = this_cpu_ptr(&kvm_host_cpu_state); > bool trap_debug = !(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY); > unsigned long mdscr; > > @@ -120,8 +104,8 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) > * This also clears MDCR_EL2_E2PB_MASK to disable guest access > * to the profiling buffer. > */ > - vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK; > - vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM | > + vcpu->arch.ctxt.mdcr_el2 = host_cxt->mdcr_el2 & MDCR_EL2_HPMN_MASK; > + vcpu->arch.ctxt.mdcr_el2 |= (MDCR_EL2_TPM | > MDCR_EL2_TPMS | > MDCR_EL2_TPMCR | > MDCR_EL2_TDRA | > @@ -130,7 +114,7 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) > /* Is Guest debugging in effect? */ > if (vcpu->guest_debug) { > /* Route all software debug exceptions to EL2 */ > - vcpu->arch.mdcr_el2 |= MDCR_EL2_TDE; > + vcpu->arch.ctxt.mdcr_el2 |= MDCR_EL2_TDE; > > /* Save guest debug state */ > save_guest_debug_regs(vcpu); > @@ -202,13 +186,13 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) > > /* Trap debug register access */ > if (trap_debug) > - vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA; > + vcpu->arch.ctxt.mdcr_el2 |= MDCR_EL2_TDA; > > /* If KDE or MDE are set, perform a full save/restore cycle. */ > if (vcpu_read_sys_reg(vcpu, MDSCR_EL1) & (DBG_MDSCR_KDE | DBG_MDSCR_MDE)) > vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY; > > - trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2); > + trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.ctxt.mdcr_el2); > trace_kvm_arm_set_dreg32("MDSCR_EL1", vcpu_read_sys_reg(vcpu, MDSCR_EL1)); > } > > diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c > index 006bd33..03b36f1 100644 > --- a/arch/arm64/kvm/hyp/switch.c > +++ b/arch/arm64/kvm/hyp/switch.c > @@ -82,7 +82,7 @@ static void __hyp_text __activate_traps_common(struct kvm_vcpu *vcpu) > */ > write_sysreg(0, pmselr_el0); > write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0); > - write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); > + write_sysreg(vcpu->arch.ctxt.mdcr_el2, mdcr_el2); > } > > static void __hyp_text __deactivate_traps_common(void) > @@ -157,14 +157,9 @@ static void deactivate_traps_vhe(struct kvm_cpu_context *host_ctxt) > > static void __hyp_text __deactivate_traps_nvhe(struct kvm_cpu_context *host_ctxt) > { > - u64 mdcr_el2 = read_sysreg(mdcr_el2); > - > __deactivate_traps_common(); > > - mdcr_el2 &= MDCR_EL2_HPMN_MASK; > - mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT; > - > - write_sysreg(mdcr_el2, mdcr_el2); > + write_sysreg(host_ctxt->mdcr_el2, mdcr_el2); > write_sysreg(host_ctxt->hcr_el2, hcr_el2); > write_sysreg(CPTR_EL2_DEFAULT, cptr_el2); > } > @@ -196,13 +191,9 @@ void activate_traps_vhe_load(struct kvm_vcpu *vcpu) > > void deactivate_traps_vhe_put(struct kvm_vcpu *vcpu) > { > - u64 mdcr_el2 = read_sysreg(mdcr_el2); > - > - mdcr_el2 &= MDCR_EL2_HPMN_MASK | > - MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT | > - MDCR_EL2_TPMS; > + struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context; > > - write_sysreg(mdcr_el2, mdcr_el2); > + write_sysreg(host_ctxt->mdcr_el2, mdcr_el2); > > __deactivate_traps_common(); > } > diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c > index 68ddc0f..42ec50f 100644 > --- a/arch/arm64/kvm/hyp/sysreg-sr.c > +++ b/arch/arm64/kvm/hyp/sysreg-sr.c > @@ -334,4 +334,10 @@ void __hyp_text __kvm_populate_host_regs(void) > host_ctxt = __hyp_this_cpu_ptr(kvm_host_cpu_state); > > host_ctxt->hcr_el2 = read_sysreg(hcr_el2); > + /* > + * Retrieve the initial value of mdcr_el2 so we can preserve > + * MDCR_EL2.HPMN which has presumably been set-up by some > + * knowledgeable bootcode. > + */ > + host_ctxt->mdcr_el2 = read_sysreg(mdcr_el2); > } > diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c > index 8e18f7f..2032a66 100644 > --- a/virt/kvm/arm/arm.c > +++ b/virt/kvm/arm/arm.c > @@ -1327,7 +1327,6 @@ static void cpu_hyp_reinit(void) > else > cpu_init_hyp_mode(NULL); > > - kvm_arm_init_debug(); > __cpu_copy_hyp_conf(); > > if (vgic_present) > -- > 2.7.4 >
On Tue, Feb 19, 2019 at 02:54:27PM +0530, Amit Daniel Kachhap wrote: > Save host MDCR_EL2 value during kvm HYP initialisation and restore > after every switch from host to guest. There should not be any > change in functionality due to this. > > The value of mdcr_el2 is now stored in struct kvm_cpu_context as > both host and guest can now use this field in a common way. Is MDCR_EL2 somehow relevant to pointer auth? It's not entirely clear why this patch is here. If this is a cleanup to align the handling of this register with how HCR_EL2 is handled, it would be good to explain that in the commit message. > Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> > Cc: Marc Zyngier <marc.zyngier@arm.com> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: Christoffer Dall <christoffer.dall@arm.com> > Cc: kvmarm@lists.cs.columbia.edu > --- > arch/arm/include/asm/kvm_host.h | 1 - > arch/arm64/include/asm/kvm_host.h | 6 ++---- > arch/arm64/kvm/debug.c | 28 ++++++---------------------- > arch/arm64/kvm/hyp/switch.c | 17 ++++------------- > arch/arm64/kvm/hyp/sysreg-sr.c | 6 ++++++ > virt/kvm/arm/arm.c | 1 - > 6 files changed, 18 insertions(+), 41 deletions(-) > > diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h > index 05706b4..704667e 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -294,7 +294,6 @@ static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} > static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} > static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} > > -static inline void kvm_arm_init_debug(void) {} > static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {} > static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {} > static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {} > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index 1b2e05b..2f1bb86 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -205,6 +205,8 @@ struct kvm_cpu_context { > > /* HYP host/guest configuration */ > u64 hcr_el2; > + u32 mdcr_el2; > + ARMv8-A says MDCR_EL2 is a 64-bit register. Bits [63:20] are currently RES0, so this is probably not a big deal. But it would be better to make this 64-bit to prevent future accidents. It may be better to make that change in a separate patch. This is probably non-urgent, since this is clearly not causing problems for anyone today. [...] Cheers ---Dave
Hi, On 2/21/19 9:21 PM, Dave Martin wrote: > On Tue, Feb 19, 2019 at 02:54:27PM +0530, Amit Daniel Kachhap wrote: >> Save host MDCR_EL2 value during kvm HYP initialisation and restore >> after every switch from host to guest. There should not be any >> change in functionality due to this. >> >> The value of mdcr_el2 is now stored in struct kvm_cpu_context as >> both host and guest can now use this field in a common way. > > Is MDCR_EL2 somehow relevant to pointer auth? > > It's not entirely clear why this patch is here. > > If this is a cleanup to align the handling of this register with > how HCR_EL2 is handled, it would be good to explain that in the commit > message. Agreed I will more information in commit message. > >> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> >> Cc: Marc Zyngier <marc.zyngier@arm.com> >> Cc: Mark Rutland <mark.rutland@arm.com> >> Cc: Christoffer Dall <christoffer.dall@arm.com> >> Cc: kvmarm@lists.cs.columbia.edu >> --- >> arch/arm/include/asm/kvm_host.h | 1 - >> arch/arm64/include/asm/kvm_host.h | 6 ++---- >> arch/arm64/kvm/debug.c | 28 ++++++---------------------- >> arch/arm64/kvm/hyp/switch.c | 17 ++++------------- >> arch/arm64/kvm/hyp/sysreg-sr.c | 6 ++++++ >> virt/kvm/arm/arm.c | 1 - >> 6 files changed, 18 insertions(+), 41 deletions(-) >> >> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h >> index 05706b4..704667e 100644 >> --- a/arch/arm/include/asm/kvm_host.h >> +++ b/arch/arm/include/asm/kvm_host.h >> @@ -294,7 +294,6 @@ static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} >> static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} >> static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} >> >> -static inline void kvm_arm_init_debug(void) {} >> static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {} >> static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {} >> static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {} >> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h >> index 1b2e05b..2f1bb86 100644 >> --- a/arch/arm64/include/asm/kvm_host.h >> +++ b/arch/arm64/include/asm/kvm_host.h >> @@ -205,6 +205,8 @@ struct kvm_cpu_context { >> >> /* HYP host/guest configuration */ >> u64 hcr_el2; >> + u32 mdcr_el2; >> + > > ARMv8-A says MDCR_EL2 is a 64-bit register. > > Bits [63:20] are currently RES0, so this is probably not a big deal. > But it would be better to make this 64-bit to prevent future accidents. > It may be better to make that change in a separate patch. Yes this a potential issue. I will fix it in a separate patch. Thanks, Amit D > > This is probably non-urgent, since this is clearly not causing problems > for anyone today. > > [...] > > Cheers > ---Dave >
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 05706b4..704667e 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -294,7 +294,6 @@ static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} -static inline void kvm_arm_init_debug(void) {} static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {} static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {} static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {} diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 1b2e05b..2f1bb86 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -205,6 +205,8 @@ struct kvm_cpu_context { /* HYP host/guest configuration */ u64 hcr_el2; + u32 mdcr_el2; + struct kvm_vcpu *__hyp_running_vcpu; }; @@ -213,9 +215,6 @@ typedef struct kvm_cpu_context kvm_cpu_context_t; struct kvm_vcpu_arch { struct kvm_cpu_context ctxt; - /* HYP configuration */ - u32 mdcr_el2; - /* Exception Information */ struct kvm_vcpu_fault_info fault; @@ -446,7 +445,6 @@ static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {} static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {} static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {} -void kvm_arm_init_debug(void); void kvm_arm_setup_debug(struct kvm_vcpu *vcpu); void kvm_arm_clear_debug(struct kvm_vcpu *vcpu); void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c index f39801e..99dc0a4 100644 --- a/arch/arm64/kvm/debug.c +++ b/arch/arm64/kvm/debug.c @@ -32,8 +32,6 @@ DBG_MDSCR_KDE | \ DBG_MDSCR_MDE) -static DEFINE_PER_CPU(u32, mdcr_el2); - /** * save/restore_guest_debug_regs * @@ -65,21 +63,6 @@ static void restore_guest_debug_regs(struct kvm_vcpu *vcpu) } /** - * kvm_arm_init_debug - grab what we need for debug - * - * Currently the sole task of this function is to retrieve the initial - * value of mdcr_el2 so we can preserve MDCR_EL2.HPMN which has - * presumably been set-up by some knowledgeable bootcode. - * - * It is called once per-cpu during CPU hyp initialisation. - */ - -void kvm_arm_init_debug(void) -{ - __this_cpu_write(mdcr_el2, kvm_call_hyp(__kvm_get_mdcr_el2)); -} - -/** * kvm_arm_reset_debug_ptr - reset the debug ptr to point to the vcpu state */ @@ -111,6 +94,7 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) { + kvm_cpu_context_t *host_cxt = this_cpu_ptr(&kvm_host_cpu_state); bool trap_debug = !(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY); unsigned long mdscr; @@ -120,8 +104,8 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) * This also clears MDCR_EL2_E2PB_MASK to disable guest access * to the profiling buffer. */ - vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK; - vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM | + vcpu->arch.ctxt.mdcr_el2 = host_cxt->mdcr_el2 & MDCR_EL2_HPMN_MASK; + vcpu->arch.ctxt.mdcr_el2 |= (MDCR_EL2_TPM | MDCR_EL2_TPMS | MDCR_EL2_TPMCR | MDCR_EL2_TDRA | @@ -130,7 +114,7 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) /* Is Guest debugging in effect? */ if (vcpu->guest_debug) { /* Route all software debug exceptions to EL2 */ - vcpu->arch.mdcr_el2 |= MDCR_EL2_TDE; + vcpu->arch.ctxt.mdcr_el2 |= MDCR_EL2_TDE; /* Save guest debug state */ save_guest_debug_regs(vcpu); @@ -202,13 +186,13 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) /* Trap debug register access */ if (trap_debug) - vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA; + vcpu->arch.ctxt.mdcr_el2 |= MDCR_EL2_TDA; /* If KDE or MDE are set, perform a full save/restore cycle. */ if (vcpu_read_sys_reg(vcpu, MDSCR_EL1) & (DBG_MDSCR_KDE | DBG_MDSCR_MDE)) vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY; - trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2); + trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.ctxt.mdcr_el2); trace_kvm_arm_set_dreg32("MDSCR_EL1", vcpu_read_sys_reg(vcpu, MDSCR_EL1)); } diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 006bd33..03b36f1 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -82,7 +82,7 @@ static void __hyp_text __activate_traps_common(struct kvm_vcpu *vcpu) */ write_sysreg(0, pmselr_el0); write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0); - write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); + write_sysreg(vcpu->arch.ctxt.mdcr_el2, mdcr_el2); } static void __hyp_text __deactivate_traps_common(void) @@ -157,14 +157,9 @@ static void deactivate_traps_vhe(struct kvm_cpu_context *host_ctxt) static void __hyp_text __deactivate_traps_nvhe(struct kvm_cpu_context *host_ctxt) { - u64 mdcr_el2 = read_sysreg(mdcr_el2); - __deactivate_traps_common(); - mdcr_el2 &= MDCR_EL2_HPMN_MASK; - mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT; - - write_sysreg(mdcr_el2, mdcr_el2); + write_sysreg(host_ctxt->mdcr_el2, mdcr_el2); write_sysreg(host_ctxt->hcr_el2, hcr_el2); write_sysreg(CPTR_EL2_DEFAULT, cptr_el2); } @@ -196,13 +191,9 @@ void activate_traps_vhe_load(struct kvm_vcpu *vcpu) void deactivate_traps_vhe_put(struct kvm_vcpu *vcpu) { - u64 mdcr_el2 = read_sysreg(mdcr_el2); - - mdcr_el2 &= MDCR_EL2_HPMN_MASK | - MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT | - MDCR_EL2_TPMS; + struct kvm_cpu_context *host_ctxt = vcpu->arch.host_cpu_context; - write_sysreg(mdcr_el2, mdcr_el2); + write_sysreg(host_ctxt->mdcr_el2, mdcr_el2); __deactivate_traps_common(); } diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index 68ddc0f..42ec50f 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -334,4 +334,10 @@ void __hyp_text __kvm_populate_host_regs(void) host_ctxt = __hyp_this_cpu_ptr(kvm_host_cpu_state); host_ctxt->hcr_el2 = read_sysreg(hcr_el2); + /* + * Retrieve the initial value of mdcr_el2 so we can preserve + * MDCR_EL2.HPMN which has presumably been set-up by some + * knowledgeable bootcode. + */ + host_ctxt->mdcr_el2 = read_sysreg(mdcr_el2); } diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 8e18f7f..2032a66 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -1327,7 +1327,6 @@ static void cpu_hyp_reinit(void) else cpu_init_hyp_mode(NULL); - kvm_arm_init_debug(); __cpu_copy_hyp_conf(); if (vgic_present)
Save host MDCR_EL2 value during kvm HYP initialisation and restore after every switch from host to guest. There should not be any change in functionality due to this. The value of mdcr_el2 is now stored in struct kvm_cpu_context as both host and guest can now use this field in a common way. Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: kvmarm@lists.cs.columbia.edu --- arch/arm/include/asm/kvm_host.h | 1 - arch/arm64/include/asm/kvm_host.h | 6 ++---- arch/arm64/kvm/debug.c | 28 ++++++---------------------- arch/arm64/kvm/hyp/switch.c | 17 ++++------------- arch/arm64/kvm/hyp/sysreg-sr.c | 6 ++++++ virt/kvm/arm/arm.c | 1 - 6 files changed, 18 insertions(+), 41 deletions(-)