2022-10-07 06:51:41

by Juergen Gross

Subject: [PATCH v2 3/3] xen/virtio: enable grant based virtio on x86

Use an x86-specific virtio_check_mem_acc_cb() for Xen in order to setup
the correct DMA ops.

Signed-off-by: Juergen Gross <[email protected]>
---
V2:
- add missing PV check in xen_virtio_mem_acc() (Oleksandr Tyshchenko)
- add xen_virtio_restricted_mem_acc() stub (Oleksandr Tyshchenko)
---
arch/x86/xen/enlighten_hvm.c | 2 +-
arch/x86/xen/enlighten_pv.c | 2 +-
drivers/xen/grant-dma-ops.c | 12 +++++++++++-
include/xen/xen-ops.h | 6 ++++++
4 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
index 1c1ac418484b..c1cd28e915a3 100644
--- a/arch/x86/xen/enlighten_hvm.c
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -212,7 +212,7 @@ static void __init xen_hvm_guest_init(void)
return;

if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT))
- virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
+ virtio_set_mem_acc_cb(xen_virtio_restricted_mem_acc);

init_hvm_pv_info();

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 9b1a58dda935..45b24c1b646a 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -112,7 +112,7 @@ static void __init xen_pv_init_platform(void)
{
/* PV guests can't operate virtio devices without grants. */
if (IS_ENABLED(CONFIG_XEN_VIRTIO))
- virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
+ virtio_set_mem_acc_cb(xen_virtio_restricted_mem_acc);

populate_extra_pte(fix_to_virt(FIX_PARAVIRT_BOOTMAP));

diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c
index c703b77b33c9..63c3f0dac066 100644
--- a/drivers/xen/grant-dma-ops.c
+++ b/drivers/xen/grant-dma-ops.c
@@ -297,7 +297,7 @@ bool xen_is_grant_dma_device(struct device *dev)

bool xen_virtio_mem_acc(struct virtio_device *dev)
{
- if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT))
+ if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT) || xen_pv_domain())
return true;

return xen_is_grant_dma_device(dev->dev.parent);
@@ -372,6 +372,16 @@ void xen_grant_setup_dma_ops(struct device *dev)
dev_err(dev, "Cannot set up Xen grant DMA ops, retain platform DMA ops\n");
}

+bool xen_virtio_restricted_mem_acc(struct virtio_device *dev)
+{
+ bool ret = xen_virtio_mem_acc(dev);
+
+ if (ret)
+ xen_grant_setup_dma_ops(dev->dev.parent);
+
+ return ret;
+}
+
MODULE_DESCRIPTION("Xen grant DMA-mapping layer");
MODULE_AUTHOR("Juergen Gross <[email protected]>");
MODULE_LICENSE("GPL");
diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index dae0f350c678..a34f4271a2e9 100644
--- a/include/xen/xen-ops.h
+++ b/include/xen/xen-ops.h
@@ -219,6 +219,7 @@ static inline void xen_preemptible_hcall_end(void) { }
void xen_grant_setup_dma_ops(struct device *dev);
bool xen_is_grant_dma_device(struct device *dev);
bool xen_virtio_mem_acc(struct virtio_device *dev);
+bool xen_virtio_restricted_mem_acc(struct virtio_device *dev);
#else
static inline void xen_grant_setup_dma_ops(struct device *dev)
{
@@ -234,6 +235,11 @@ static inline bool xen_virtio_mem_acc(struct virtio_device *dev)
{
return false;
}
+
+static inline bool xen_virtio_restricted_mem_acc(struct virtio_device *dev)
+{
+ return false;
+}
#endif /* CONFIG_XEN_GRANT_DMA_OPS */

#endif /* INCLUDE_XEN_OPS_H */
--
2.35.3

2022-10-07 14:08:25

by Oleksandr Tyshchenko

Subject: Re: [PATCH v2 3/3] xen/virtio: enable grant based virtio on x86

On 07.10.22 09:41, Juergen Gross wrote:

Hello Juergen

> Use an x86-specific virtio_check_mem_acc_cb() for Xen in order to setup
> the correct DMA ops.
>
> Signed-off-by: Juergen Gross <[email protected]>
> ---
> V2:
> - add missing PV check in xen_virtio_mem_acc() (Oleksandr Tyshchenko)
> - add xen_virtio_restricted_mem_acc() stub (Oleksandr Tyshchenko)


Reviewed-by: Oleksandr Tyshchenko <[email protected]> #
common code


> ---
> arch/x86/xen/enlighten_hvm.c | 2 +-
> arch/x86/xen/enlighten_pv.c | 2 +-
> drivers/xen/grant-dma-ops.c | 12 +++++++++++-
> include/xen/xen-ops.h | 6 ++++++
> 4 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
> index 1c1ac418484b..c1cd28e915a3 100644
> --- a/arch/x86/xen/enlighten_hvm.c
> +++ b/arch/x86/xen/enlighten_hvm.c
> @@ -212,7 +212,7 @@ static void __init xen_hvm_guest_init(void)
> return;
>
> if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT))
> - virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
> + virtio_set_mem_acc_cb(xen_virtio_restricted_mem_acc);
>
> init_hvm_pv_info();
>
> diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
> index 9b1a58dda935..45b24c1b646a 100644
> --- a/arch/x86/xen/enlighten_pv.c
> +++ b/arch/x86/xen/enlighten_pv.c
> @@ -112,7 +112,7 @@ static void __init xen_pv_init_platform(void)
> {
> /* PV guests can't operate virtio devices without grants. */
> if (IS_ENABLED(CONFIG_XEN_VIRTIO))
> - virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
> + virtio_set_mem_acc_cb(xen_virtio_restricted_mem_acc);
>
> populate_extra_pte(fix_to_virt(FIX_PARAVIRT_BOOTMAP));
>
> diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c
> index c703b77b33c9..63c3f0dac066 100644
> --- a/drivers/xen/grant-dma-ops.c
> +++ b/drivers/xen/grant-dma-ops.c
> @@ -297,7 +297,7 @@ bool xen_is_grant_dma_device(struct device *dev)
>
> bool xen_virtio_mem_acc(struct virtio_device *dev)
> {
> - if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT))
> + if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT) || xen_pv_domain())
> return true;
>
> return xen_is_grant_dma_device(dev->dev.parent);
> @@ -372,6 +372,16 @@ void xen_grant_setup_dma_ops(struct device *dev)
> dev_err(dev, "Cannot set up Xen grant DMA ops, retain platform DMA ops\n");
> }
>
> +bool xen_virtio_restricted_mem_acc(struct virtio_device *dev)
> +{
> + bool ret = xen_virtio_mem_acc(dev);
> +
> + if (ret)
> + xen_grant_setup_dma_ops(dev->dev.parent);
> +
> + return ret;
> +}
> +
> MODULE_DESCRIPTION("Xen grant DMA-mapping layer");
> MODULE_AUTHOR("Juergen Gross <[email protected]>");
> MODULE_LICENSE("GPL");
> diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
> index dae0f350c678..a34f4271a2e9 100644
> --- a/include/xen/xen-ops.h
> +++ b/include/xen/xen-ops.h
> @@ -219,6 +219,7 @@ static inline void xen_preemptible_hcall_end(void) { }
> void xen_grant_setup_dma_ops(struct device *dev);
> bool xen_is_grant_dma_device(struct device *dev);
> bool xen_virtio_mem_acc(struct virtio_device *dev);
> +bool xen_virtio_restricted_mem_acc(struct virtio_device *dev);
> #else
> static inline void xen_grant_setup_dma_ops(struct device *dev)
> {
> @@ -234,6 +235,11 @@ static inline bool xen_virtio_mem_acc(struct virtio_device *dev)
> {
> return false;
> }
> +
> +static inline bool xen_virtio_restricted_mem_acc(struct virtio_device *dev)
> +{
> + return false;
> +}
> #endif /* CONFIG_XEN_GRANT_DMA_OPS */
>
> #endif /* INCLUDE_XEN_OPS_H */

--
Regards,

Oleksandr Tyshchenko

2022-10-07 16:26:39

by Boris Ostrovsky

Subject: Re: [PATCH v2 3/3] xen/virtio: enable grant based virtio on x86

On 10/7/22 10:00 AM, Oleksandr Tyshchenko wrote:
> On 07.10.22 09:41, Juergen Gross wrote:
>
> Hello Juergen
>
>> Use an x86-specific virtio_check_mem_acc_cb() for Xen in order to setup
>> the correct DMA ops.
>>
>> Signed-off-by: Juergen Gross <[email protected]>
>> ---
>> V2:
>> - add missing PV check in xen_virtio_mem_acc() (Oleksandr Tyshchenko)
>> - add xen_virtio_restricted_mem_acc() stub (Oleksandr Tyshchenko)
>
> Reviewed-by: Oleksandr Tyshchenko <[email protected]> #
> common code



Reviewed-by: Boris Ostrovsky <[email protected]>