1. Patchew
  2. Xen
  3. [PATCH v2 00/10] Get rid of READ/WRITE_SYSREG32
  4. View patch

[PATCH v2 02/10] arm/domain: Get rid of READ/WRITE_SYSREG32

Michal Orzel posted 10 patches 4 years, 9 months ago
[PATCH v2 02/10] arm/domain: Get rid of READ/WRITE_SYSREG32
Posted by Michal Orzel 4 years, 9 months ago 
AArch64 registers are 64bit whereas AArch32 registers
are 32bit or 64bit. MSR/MRS are expecting 64bit values thus
we should get rid of helpers READ/WRITE_SYSREG32
in favour of using READ/WRITE_SYSREG.
We should also use register_t type when reading sysregs
which can correspond to uint64_t or uint32_t.
Even though many AArch64 registers have upper 32bit reserved
it does not mean that they can't be widen in the future.

Modify type of register cntkctl to register_t.
Modify accesses to thumbee registers to use READ/WRITE_SYSREG.
No need to change type of thumbee registers to register_t as they
only exist on arm32.

Signed-off-by: Michal Orzel <michal.orzel@arm.com>
---
Changes since v1:
-Move modification of ACTLR into seperate patch
---
 xen/arch/arm/domain.c        | 18 +++++++++---------
 xen/include/asm-arm/domain.h |  2 +-
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index bdd3d3e5b5..621f518b83 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -113,13 +113,13 @@ static void ctxt_switch_from(struct vcpu *p)
     p->arch.tpidr_el1 = READ_SYSREG(TPIDR_EL1);
 
     /* Arch timer */
-    p->arch.cntkctl = READ_SYSREG32(CNTKCTL_EL1);
+    p->arch.cntkctl = READ_SYSREG(CNTKCTL_EL1);
     virt_timer_save(p);
 
     if ( is_32bit_domain(p->domain) && cpu_has_thumbee )
     {
-        p->arch.teecr = READ_SYSREG32(TEECR32_EL1);
-        p->arch.teehbr = READ_SYSREG32(TEEHBR32_EL1);
+        p->arch.teecr = READ_SYSREG(TEECR32_EL1);
+        p->arch.teehbr = READ_SYSREG(TEEHBR32_EL1);
     }
 
 #ifdef CONFIG_ARM_32
@@ -175,7 +175,7 @@ static void ctxt_switch_from(struct vcpu *p)
 
 static void ctxt_switch_to(struct vcpu *n)
 {
-    uint32_t vpidr;
+    register_t vpidr;
 
     /* When the idle VCPU is running, Xen will always stay in hypervisor
      * mode. Therefore we don't need to restore the context of an idle VCPU.
@@ -183,8 +183,8 @@ static void ctxt_switch_to(struct vcpu *n)
     if ( is_idle_vcpu(n) )
         return;
 
-    vpidr = READ_SYSREG32(MIDR_EL1);
-    WRITE_SYSREG32(vpidr, VPIDR_EL2);
+    vpidr = READ_SYSREG(MIDR_EL1);
+    WRITE_SYSREG(vpidr, VPIDR_EL2);
     WRITE_SYSREG(n->arch.vmpidr, VMPIDR_EL2);
 
     /* VGIC */
@@ -257,8 +257,8 @@ static void ctxt_switch_to(struct vcpu *n)
 
     if ( is_32bit_domain(n->domain) && cpu_has_thumbee )
     {
-        WRITE_SYSREG32(n->arch.teecr, TEECR32_EL1);
-        WRITE_SYSREG32(n->arch.teehbr, TEEHBR32_EL1);
+        WRITE_SYSREG(n->arch.teecr, TEECR32_EL1);
+        WRITE_SYSREG(n->arch.teehbr, TEEHBR32_EL1);
     }
 
 #ifdef CONFIG_ARM_32
@@ -274,7 +274,7 @@ static void ctxt_switch_to(struct vcpu *n)
 
     /* This is could trigger an hardware interrupt from the virtual
      * timer. The interrupt needs to be injected into the guest. */
-    WRITE_SYSREG32(n->arch.cntkctl, CNTKCTL_EL1);
+    WRITE_SYSREG(n->arch.cntkctl, CNTKCTL_EL1);
     virt_timer_restore(n);
 }
 
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index 0a74df9931..c6b59ee755 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -190,7 +190,7 @@ struct arch_vcpu
     struct vgic_cpu vgic;
 
     /* Timer registers  */
-    uint32_t cntkctl;
+    register_t cntkctl;
 
     struct vtimer phys_timer;
     struct vtimer virt_timer;
-- 
2.29.0
Re: [PATCH v2 02/10] arm/domain: Get rid of READ/WRITE_SYSREG32
Posted by Julien Grall 4 years, 9 months ago 
Hi Michal,

On 27/04/2021 10:35, Michal Orzel wrote:
> AArch64 registers are 64bit whereas AArch32 registers
> are 32bit or 64bit. MSR/MRS are expecting 64bit values thus
> we should get rid of helpers READ/WRITE_SYSREG32
> in favour of using READ/WRITE_SYSREG.
> We should also use register_t type when reading sysregs
> which can correspond to uint64_t or uint32_t.
> Even though many AArch64 registers have upper 32bit reserved
> it does not mean that they can't be widen in the future.
> 
> Modify type of register cntkctl to register_t.
> Modify accesses to thumbee registers to use READ/WRITE_SYSREG.
> No need to change type of thumbee registers to register_t as they
> only exist on arm32.

This is a bit ambiguous, I think in this context you mean it is only 
usable by 32-bit domain but should really be only accessed on Armv7 as 
they were restrospectively dropped on Armv8.

> Signed-off-by: Michal Orzel <michal.orzel@arm.com>
> ---
> Changes since v1:
> -Move modification of ACTLR into seperate patch
> ---
>   xen/arch/arm/domain.c        | 18 +++++++++---------
>   xen/include/asm-arm/domain.h |  2 +-
>   2 files changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
> index bdd3d3e5b5..621f518b83 100644
> --- a/xen/arch/arm/domain.c
> +++ b/xen/arch/arm/domain.c
> @@ -113,13 +113,13 @@ static void ctxt_switch_from(struct vcpu *p)
>       p->arch.tpidr_el1 = READ_SYSREG(TPIDR_EL1);
>   
>       /* Arch timer */
> -    p->arch.cntkctl = READ_SYSREG32(CNTKCTL_EL1);
> +    p->arch.cntkctl = READ_SYSREG(CNTKCTL_EL1);
>       virt_timer_save(p);
>   
>       if ( is_32bit_domain(p->domain) && cpu_has_thumbee )
>       {
> -        p->arch.teecr = READ_SYSREG32(TEECR32_EL1);
> -        p->arch.teehbr = READ_SYSREG32(TEEHBR32_EL1);
> +        p->arch.teecr = READ_SYSREG(TEECR32_EL1);
> +        p->arch.teehbr = READ_SYSREG(TEEHBR32_EL1);
>       }
>   
>   #ifdef CONFIG_ARM_32
> @@ -175,7 +175,7 @@ static void ctxt_switch_from(struct vcpu *p)
>   
>   static void ctxt_switch_to(struct vcpu *n)
>   {
> -    uint32_t vpidr;
> +    register_t vpidr;
>   
>       /* When the idle VCPU is running, Xen will always stay in hypervisor
>        * mode. Therefore we don't need to restore the context of an idle VCPU.
> @@ -183,8 +183,8 @@ static void ctxt_switch_to(struct vcpu *n)
>       if ( is_idle_vcpu(n) )
>           return;
>   
> -    vpidr = READ_SYSREG32(MIDR_EL1);
> -    WRITE_SYSREG32(vpidr, VPIDR_EL2);
> +    vpidr = READ_SYSREG(MIDR_EL1);
> +    WRITE_SYSREG(vpidr, VPIDR_EL2);
>       WRITE_SYSREG(n->arch.vmpidr, VMPIDR_EL2);
>   
>       /* VGIC */
> @@ -257,8 +257,8 @@ static void ctxt_switch_to(struct vcpu *n)
>   
>       if ( is_32bit_domain(n->domain) && cpu_has_thumbee )
>       {
> -        WRITE_SYSREG32(n->arch.teecr, TEECR32_EL1);
> -        WRITE_SYSREG32(n->arch.teehbr, TEEHBR32_EL1);
> +        WRITE_SYSREG(n->arch.teecr, TEECR32_EL1);
> +        WRITE_SYSREG(n->arch.teehbr, TEEHBR32_EL1);
>       }
>   
>   #ifdef CONFIG_ARM_32
> @@ -274,7 +274,7 @@ static void ctxt_switch_to(struct vcpu *n)
>   
>       /* This is could trigger an hardware interrupt from the virtual
>        * timer. The interrupt needs to be injected into the guest. */
> -    WRITE_SYSREG32(n->arch.cntkctl, CNTKCTL_EL1);
> +    WRITE_SYSREG(n->arch.cntkctl, CNTKCTL_EL1);
>       virt_timer_restore(n);
>   }
>   
> diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
> index 0a74df9931..c6b59ee755 100644
> --- a/xen/include/asm-arm/domain.h
> +++ b/xen/include/asm-arm/domain.h
> @@ -190,7 +190,7 @@ struct arch_vcpu
>       struct vgic_cpu vgic;
>   
>       /* Timer registers  */
> -    uint32_t cntkctl;
> +    register_t cntkctl;
>   
>       struct vtimer phys_timer;
>       struct vtimer virt_timer;
> 

-- 
Julien Grall
Re: [PATCH v2 02/10] arm/domain: Get rid of READ/WRITE_SYSREG32
Posted by Michal Orzel 4 years, 9 months ago 
Hi Julien,

On 27.04.2021 11:45, Julien Grall wrote:
> Hi Michal,
> 
> On 27/04/2021 10:35, Michal Orzel wrote:
>> AArch64 registers are 64bit whereas AArch32 registers
>> are 32bit or 64bit. MSR/MRS are expecting 64bit values thus
>> we should get rid of helpers READ/WRITE_SYSREG32
>> in favour of using READ/WRITE_SYSREG.
>> We should also use register_t type when reading sysregs
>> which can correspond to uint64_t or uint32_t.
>> Even though many AArch64 registers have upper 32bit reserved
>> it does not mean that they can't be widen in the future.
>>
>> Modify type of register cntkctl to register_t.
>> Modify accesses to thumbee registers to use READ/WRITE_SYSREG.
>> No need to change type of thumbee registers to register_t as they
>> only exist on arm32.
> 
> This is a bit ambiguous, I think in this context you mean it is only usable by 32-bit domain but should really be only accessed on Armv7 as they were restrospectively dropped on Armv8.
> 
Is the following ok for a v3?:
"
...
Modify type of register cntkctl to register_t.

Modify accesses to thumbee registers to use READ/WRITE_SYSREG.
Thumbee registers are only usable by a 32bit domain and in fact
should be only accessed on ARMv7 as they were retrospectively dropped
on ARMv8.
"
>> Signed-off-by: Michal Orzel <michal.orzel@arm.com>
>> ---
>> Changes since v1:
>> -Move modification of ACTLR into seperate patch
>> ---
>>   xen/arch/arm/domain.c        | 18 +++++++++---------
>>   xen/include/asm-arm/domain.h |  2 +-
>>   2 files changed, 10 insertions(+), 10 deletions(-)
>>
>> diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
>> index bdd3d3e5b5..621f518b83 100644
>> --- a/xen/arch/arm/domain.c
>> +++ b/xen/arch/arm/domain.c
>> @@ -113,13 +113,13 @@ static void ctxt_switch_from(struct vcpu *p)
>>       p->arch.tpidr_el1 = READ_SYSREG(TPIDR_EL1);
>>         /* Arch timer */
>> -    p->arch.cntkctl = READ_SYSREG32(CNTKCTL_EL1);
>> +    p->arch.cntkctl = READ_SYSREG(CNTKCTL_EL1);
>>       virt_timer_save(p);
>>         if ( is_32bit_domain(p->domain) && cpu_has_thumbee )
>>       {
>> -        p->arch.teecr = READ_SYSREG32(TEECR32_EL1);
>> -        p->arch.teehbr = READ_SYSREG32(TEEHBR32_EL1);
>> +        p->arch.teecr = READ_SYSREG(TEECR32_EL1);
>> +        p->arch.teehbr = READ_SYSREG(TEEHBR32_EL1);
>>       }
>>     #ifdef CONFIG_ARM_32
>> @@ -175,7 +175,7 @@ static void ctxt_switch_from(struct vcpu *p)
>>     static void ctxt_switch_to(struct vcpu *n)
>>   {
>> -    uint32_t vpidr;
>> +    register_t vpidr;
>>         /* When the idle VCPU is running, Xen will always stay in hypervisor
>>        * mode. Therefore we don't need to restore the context of an idle VCPU.
>> @@ -183,8 +183,8 @@ static void ctxt_switch_to(struct vcpu *n)
>>       if ( is_idle_vcpu(n) )
>>           return;
>>   -    vpidr = READ_SYSREG32(MIDR_EL1);
>> -    WRITE_SYSREG32(vpidr, VPIDR_EL2);
>> +    vpidr = READ_SYSREG(MIDR_EL1);
>> +    WRITE_SYSREG(vpidr, VPIDR_EL2);
>>       WRITE_SYSREG(n->arch.vmpidr, VMPIDR_EL2);
>>         /* VGIC */
>> @@ -257,8 +257,8 @@ static void ctxt_switch_to(struct vcpu *n)
>>         if ( is_32bit_domain(n->domain) && cpu_has_thumbee )
>>       {
>> -        WRITE_SYSREG32(n->arch.teecr, TEECR32_EL1);
>> -        WRITE_SYSREG32(n->arch.teehbr, TEEHBR32_EL1);
>> +        WRITE_SYSREG(n->arch.teecr, TEECR32_EL1);
>> +        WRITE_SYSREG(n->arch.teehbr, TEEHBR32_EL1);
>>       }
>>     #ifdef CONFIG_ARM_32
>> @@ -274,7 +274,7 @@ static void ctxt_switch_to(struct vcpu *n)
>>         /* This is could trigger an hardware interrupt from the virtual
>>        * timer. The interrupt needs to be injected into the guest. */
>> -    WRITE_SYSREG32(n->arch.cntkctl, CNTKCTL_EL1);
>> +    WRITE_SYSREG(n->arch.cntkctl, CNTKCTL_EL1);
>>       virt_timer_restore(n);
>>   }
>>   diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
>> index 0a74df9931..c6b59ee755 100644
>> --- a/xen/include/asm-arm/domain.h
>> +++ b/xen/include/asm-arm/domain.h
>> @@ -190,7 +190,7 @@ struct arch_vcpu
>>       struct vgic_cpu vgic;
>>         /* Timer registers  */
>> -    uint32_t cntkctl;
>> +    register_t cntkctl;
>>         struct vtimer phys_timer;
>>       struct vtimer virt_timer;
>>
>

Patchew 2.1-devel-b67e4c2

© 2016 - 2026 Red Hat, Inc.