[v3,7/9] KVM: PPC: Ultravisor: Restrict LDBAR access
diff mbox series

Message ID 20190606173614.32090-8-cclaudio@linux.ibm.com
State Superseded
Headers show
Series
  • kvmppc: Paravirtualize KVM to support ultravisor
Related show

Commit Message

Claudio Carvalho June 6, 2019, 5:36 p.m. UTC
When the ultravisor firmware is available, it takes control over the
LDBAR register. In this case, thread-imc updates and save/restore
operations on the LDBAR register are handled by ultravisor.

Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
 arch/powerpc/kvm/book3s_hv_rmhandlers.S   | 2 ++
 arch/powerpc/platforms/powernv/idle.c     | 6 ++++--
 arch/powerpc/platforms/powernv/opal-imc.c | 7 +++++++
 3 files changed, 13 insertions(+), 2 deletions(-)

Comments

maddy June 7, 2019, 4:48 a.m. UTC | #1
On 06/06/19 11:06 PM, Claudio Carvalho wrote:
> When the ultravisor firmware is available, it takes control over the
> LDBAR register. In this case, thread-imc updates and save/restore
> operations on the LDBAR register are handled by ultravisor.
>
> Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
> Signed-off-by: Ram Pai <linuxram@us.ibm.com>
> ---
>   arch/powerpc/kvm/book3s_hv_rmhandlers.S   | 2 ++
>   arch/powerpc/platforms/powernv/idle.c     | 6 ++++--
>   arch/powerpc/platforms/powernv/opal-imc.c | 7 +++++++
>   3 files changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> index f9b2620fbecd..cffb365d9d02 100644
> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> @@ -375,8 +375,10 @@ BEGIN_FTR_SECTION
>   	mtspr	SPRN_RPR, r0
>   	ld	r0, KVM_SPLIT_PMMAR(r6)
>   	mtspr	SPRN_PMMAR, r0
> +BEGIN_FW_FTR_SECTION_NESTED(70)
>   	ld	r0, KVM_SPLIT_LDBAR(r6)
>   	mtspr	SPRN_LDBAR, r0
> +END_FW_FTR_SECTION_NESTED(FW_FEATURE_ULTRAVISOR, 0, 70)
>   	isync
>   FTR_SECTION_ELSE
>   	/* On P9 we use the split_info for coordinating LPCR changes */
> diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
> index c9133f7908ca..fd62435e3267 100644
> --- a/arch/powerpc/platforms/powernv/idle.c
> +++ b/arch/powerpc/platforms/powernv/idle.c
> @@ -679,7 +679,8 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
>   		sprs.ptcr	= mfspr(SPRN_PTCR);
>   		sprs.rpr	= mfspr(SPRN_RPR);
>   		sprs.tscr	= mfspr(SPRN_TSCR);
> -		sprs.ldbar	= mfspr(SPRN_LDBAR);
> +		if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
> +			sprs.ldbar	= mfspr(SPRN_LDBAR);
>
>   		sprs_saved = true;
>
> @@ -762,7 +763,8 @@ static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
>   	mtspr(SPRN_PTCR,	sprs.ptcr);
>   	mtspr(SPRN_RPR,		sprs.rpr);
>   	mtspr(SPRN_TSCR,	sprs.tscr);
> -	mtspr(SPRN_LDBAR,	sprs.ldbar);
> +	if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
> +		mtspr(SPRN_LDBAR,	sprs.ldbar);
>
>   	if (pls >= pnv_first_tb_loss_level) {
>   		/* TB loss */
> diff --git a/arch/powerpc/platforms/powernv/opal-imc.c b/arch/powerpc/platforms/powernv/opal-imc.c
> index 1b6932890a73..e9b641d313fb 100644
> --- a/arch/powerpc/platforms/powernv/opal-imc.c
> +++ b/arch/powerpc/platforms/powernv/opal-imc.c
> @@ -254,6 +254,13 @@ static int opal_imc_counters_probe(struct platform_device *pdev)
>   	bool core_imc_reg = false, thread_imc_reg = false;
>   	u32 type;
>
> +	/*
> +	 * When the Ultravisor is enabled, it is responsible for thread-imc
> +	 * updates
> +	 */

Would prefer the comment to be "Disable IMC devices, when Ultravisor is 
enabled"
Rest looks good.
Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>

> +	if (firmware_has_feature(FW_FEATURE_ULTRAVISOR))
> +		return -EACCES;
> +
>   	/*
>   	 * Check whether this is kdump kernel. If yes, force the engines to
>   	 * stop and return.
Claudio Carvalho June 7, 2019, 12:34 p.m. UTC | #2
On 6/7/19 1:48 AM, Madhavan Srinivasan wrote:
>
> On 06/06/19 11:06 PM, Claudio Carvalho wrote:
>> When the ultravisor firmware is available, it takes control over the
>> LDBAR register. In this case, thread-imc updates and save/restore
>> operations on the LDBAR register are handled by ultravisor.
>>
>> Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
>> Signed-off-by: Ram Pai <linuxram@us.ibm.com>
>> ---
>>   arch/powerpc/kvm/book3s_hv_rmhandlers.S   | 2 ++
>>   arch/powerpc/platforms/powernv/idle.c     | 6 ++++--
>>   arch/powerpc/platforms/powernv/opal-imc.c | 7 +++++++
>>   3 files changed, 13 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
>> b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
>> index f9b2620fbecd..cffb365d9d02 100644
>> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
>> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
>> @@ -375,8 +375,10 @@ BEGIN_FTR_SECTION
>>       mtspr    SPRN_RPR, r0
>>       ld    r0, KVM_SPLIT_PMMAR(r6)
>>       mtspr    SPRN_PMMAR, r0
>> +BEGIN_FW_FTR_SECTION_NESTED(70)
>>       ld    r0, KVM_SPLIT_LDBAR(r6)
>>       mtspr    SPRN_LDBAR, r0
>> +END_FW_FTR_SECTION_NESTED(FW_FEATURE_ULTRAVISOR, 0, 70)
>>       isync
>>   FTR_SECTION_ELSE
>>       /* On P9 we use the split_info for coordinating LPCR changes */
>> diff --git a/arch/powerpc/platforms/powernv/idle.c
>> b/arch/powerpc/platforms/powernv/idle.c
>> index c9133f7908ca..fd62435e3267 100644
>> --- a/arch/powerpc/platforms/powernv/idle.c
>> +++ b/arch/powerpc/platforms/powernv/idle.c
>> @@ -679,7 +679,8 @@ static unsigned long power9_idle_stop(unsigned long
>> psscr, bool mmu_on)
>>           sprs.ptcr    = mfspr(SPRN_PTCR);
>>           sprs.rpr    = mfspr(SPRN_RPR);
>>           sprs.tscr    = mfspr(SPRN_TSCR);
>> -        sprs.ldbar    = mfspr(SPRN_LDBAR);
>> +        if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
>> +            sprs.ldbar    = mfspr(SPRN_LDBAR);
>>
>>           sprs_saved = true;
>>
>> @@ -762,7 +763,8 @@ static unsigned long power9_idle_stop(unsigned long
>> psscr, bool mmu_on)
>>       mtspr(SPRN_PTCR,    sprs.ptcr);
>>       mtspr(SPRN_RPR,        sprs.rpr);
>>       mtspr(SPRN_TSCR,    sprs.tscr);
>> -    mtspr(SPRN_LDBAR,    sprs.ldbar);
>> +    if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
>> +        mtspr(SPRN_LDBAR,    sprs.ldbar);
>>
>>       if (pls >= pnv_first_tb_loss_level) {
>>           /* TB loss */
>> diff --git a/arch/powerpc/platforms/powernv/opal-imc.c
>> b/arch/powerpc/platforms/powernv/opal-imc.c
>> index 1b6932890a73..e9b641d313fb 100644
>> --- a/arch/powerpc/platforms/powernv/opal-imc.c
>> +++ b/arch/powerpc/platforms/powernv/opal-imc.c
>> @@ -254,6 +254,13 @@ static int opal_imc_counters_probe(struct
>> platform_device *pdev)
>>       bool core_imc_reg = false, thread_imc_reg = false;
>>       u32 type;
>>
>> +    /*
>> +     * When the Ultravisor is enabled, it is responsible for thread-imc
>> +     * updates
>> +     */
>
> Would prefer the comment to be "Disable IMC devices, when Ultravisor is
> enabled"
> Rest looks good.
> Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>


Thanks Maddy. I applied that change to the next version.

Claudio


>
>> +    if (firmware_has_feature(FW_FEATURE_ULTRAVISOR))
>> +        return -EACCES;
>> +
>>       /*
>>        * Check whether this is kdump kernel. If yes, force the engines to
>>        * stop and return.
Paul Mackerras June 15, 2019, 7:43 a.m. UTC | #3
On Thu, Jun 06, 2019 at 02:36:12PM -0300, Claudio Carvalho wrote:
> When the ultravisor firmware is available, it takes control over the
> LDBAR register. In this case, thread-imc updates and save/restore
> operations on the LDBAR register are handled by ultravisor.
> 
> Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
> Signed-off-by: Ram Pai <linuxram@us.ibm.com>

Acked-by: Paul Mackerras <paulus@ozlabs.org>

Just a note on the signed-off-by: it's a bit weird to have Ram's
signoff when he is neither the author nor the sender of the patch.
The author is assumed to be Claudio; if that is not correct then the
patch should have a From: line at the start telling us who the author
is, and ideally that person should have a signoff line before
Claudio's signoff as the sender of the patch.

Paul.
Ram Pai June 16, 2019, 1:10 a.m. UTC | #4
On Sat, Jun 15, 2019 at 05:43:34PM +1000, Paul Mackerras wrote:
> On Thu, Jun 06, 2019 at 02:36:12PM -0300, Claudio Carvalho wrote:
> > When the ultravisor firmware is available, it takes control over the
> > LDBAR register. In this case, thread-imc updates and save/restore
> > operations on the LDBAR register are handled by ultravisor.
> > 
> > Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
> > Signed-off-by: Ram Pai <linuxram@us.ibm.com>
> 
> Acked-by: Paul Mackerras <paulus@ozlabs.org>
> 
> Just a note on the signed-off-by: it's a bit weird to have Ram's
> signoff when he is neither the author nor the sender of the patch.
> The author is assumed to be Claudio; if that is not correct then the
> patch should have a From: line at the start telling us who the author
> is, and ideally that person should have a signoff line before
> Claudio's signoff as the sender of the patch.

Ryan originally wrote this patch, which I than modified,
before Claudio further modified it to its current form.

So I think the author should be Ryan.

RP

Patch
diff mbox series

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index f9b2620fbecd..cffb365d9d02 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -375,8 +375,10 @@  BEGIN_FTR_SECTION
 	mtspr	SPRN_RPR, r0
 	ld	r0, KVM_SPLIT_PMMAR(r6)
 	mtspr	SPRN_PMMAR, r0
+BEGIN_FW_FTR_SECTION_NESTED(70)
 	ld	r0, KVM_SPLIT_LDBAR(r6)
 	mtspr	SPRN_LDBAR, r0
+END_FW_FTR_SECTION_NESTED(FW_FEATURE_ULTRAVISOR, 0, 70)
 	isync
 FTR_SECTION_ELSE
 	/* On P9 we use the split_info for coordinating LPCR changes */
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index c9133f7908ca..fd62435e3267 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -679,7 +679,8 @@  static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
 		sprs.ptcr	= mfspr(SPRN_PTCR);
 		sprs.rpr	= mfspr(SPRN_RPR);
 		sprs.tscr	= mfspr(SPRN_TSCR);
-		sprs.ldbar	= mfspr(SPRN_LDBAR);
+		if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
+			sprs.ldbar	= mfspr(SPRN_LDBAR);
 
 		sprs_saved = true;
 
@@ -762,7 +763,8 @@  static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
 	mtspr(SPRN_PTCR,	sprs.ptcr);
 	mtspr(SPRN_RPR,		sprs.rpr);
 	mtspr(SPRN_TSCR,	sprs.tscr);
-	mtspr(SPRN_LDBAR,	sprs.ldbar);
+	if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
+		mtspr(SPRN_LDBAR,	sprs.ldbar);
 
 	if (pls >= pnv_first_tb_loss_level) {
 		/* TB loss */
diff --git a/arch/powerpc/platforms/powernv/opal-imc.c b/arch/powerpc/platforms/powernv/opal-imc.c
index 1b6932890a73..e9b641d313fb 100644
--- a/arch/powerpc/platforms/powernv/opal-imc.c
+++ b/arch/powerpc/platforms/powernv/opal-imc.c
@@ -254,6 +254,13 @@  static int opal_imc_counters_probe(struct platform_device *pdev)
 	bool core_imc_reg = false, thread_imc_reg = false;
 	u32 type;
 
+	/*
+	 * When the Ultravisor is enabled, it is responsible for thread-imc
+	 * updates
+	 */
+	if (firmware_has_feature(FW_FEATURE_ULTRAVISOR))
+		return -EACCES;
+
 	/*
 	 * Check whether this is kdump kernel. If yes, force the engines to
 	 * stop and return.