iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

iommu/vt-d: Enlightened PASID allocation

Browse Source 
Enabling IOMMU in a guest requires communication with the host
driver for certain aspects. Use of PASID ID to enable Shared Virtual
Addressing (SVA) requires managing PASID's in the host. VT-d 3.0 spec
provides a Virtual Command Register (VCMD) to facilitate this.
Writes to this register in the guest are trapped by vIOMMU which
proxies the call to the host driver.

This virtual command interface consists of a capability register,
a virtual command register, and a virtual response register. Refer
to section 10.4.42, 10.4.43, 10.4.44 for more information.

This patch adds the enlightened PASID allocation/free interfaces
via the virtual command interface.

Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20200516062101.29541-8-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Lu Baolu 2020-05-16 14:20:50 +08:00 committed by Joerg Roedel
parent 6ee1b77ba3
commit 24f27d32ab
3 changed files with 70 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
drivers/iommu/intel-pasid.c
View File

@ -27,6 +27,63 @@
static DEFINE_SPINLOCK(pasid_lock);
u32 intel_pasid_max_id = PASID_MAX;
int vcmd_alloc_pasid(struct intel_iommu *iommu, unsigned int *pasid)
{
unsigned long flags;
u8 status_code;
int ret = 0;
u64 res;
raw_spin_lock_irqsave(&iommu->register_lock, flags);
dmar_writeq(iommu->reg + DMAR_VCMD_REG, VCMD_CMD_ALLOC);
IOMMU_WAIT_OP(iommu, DMAR_VCRSP_REG, dmar_readq,
!(res & VCMD_VRSP_IP), res);
raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
status_code = VCMD_VRSP_SC(res);
switch (status_code) {
case VCMD_VRSP_SC_SUCCESS:
*pasid = VCMD_VRSP_RESULT_PASID(res);
break;
case VCMD_VRSP_SC_NO_PASID_AVAIL:
pr_info("IOMMU: %s: No PASID available\n", iommu->name);
ret = -ENOSPC;
break;
default:
ret = -ENODEV;
pr_warn("IOMMU: %s: Unexpected error code %d\n",
iommu->name, status_code);
}
return ret;
}
void vcmd_free_pasid(struct intel_iommu *iommu, unsigned int pasid)
{
unsigned long flags;
u8 status_code;
u64 res;
raw_spin_lock_irqsave(&iommu->register_lock, flags);
dmar_writeq(iommu->reg + DMAR_VCMD_REG,
VCMD_CMD_OPERAND(pasid) | VCMD_CMD_FREE);
IOMMU_WAIT_OP(iommu, DMAR_VCRSP_REG, dmar_readq,
!(res & VCMD_VRSP_IP), res);
raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
status_code = VCMD_VRSP_SC(res);
switch (status_code) {
case VCMD_VRSP_SC_SUCCESS:
break;
case VCMD_VRSP_SC_INVALID_PASID:
pr_info("IOMMU: %s: Invalid PASID\n", iommu->name);
break;
default:
pr_warn("IOMMU: %s: Unexpected error code %d\n",
iommu->name, status_code);
}
}
/*
* Per device pasid table management:
*/

13
drivers/iommu/intel-pasid.h
View File

@ -23,6 +23,16 @@
#define is_pasid_enabled(entry) (((entry)->lo >> 3) & 0x1)
#define get_pasid_dir_size(entry) (1 << ((((entry)->lo >> 9) & 0x7) + 7))
/* Virtual command interface for enlightened pasid management. */
#define VCMD_CMD_ALLOC 0x1
#define VCMD_CMD_FREE 0x2
#define VCMD_VRSP_IP 0x1
#define VCMD_VRSP_SC(e) (((e) >> 1) & 0x3)
#define VCMD_VRSP_SC_SUCCESS 0
#define VCMD_VRSP_SC_NO_PASID_AVAIL 1
#define VCMD_VRSP_SC_INVALID_PASID 1
#define VCMD_VRSP_RESULT_PASID(e) (((e) >> 8) & 0xfffff)
#define VCMD_CMD_OPERAND(e) ((e) << 8)
/*
* Domain ID reserved for pasid entries programmed for first-level
* only and pass-through transfer modes.
@ -111,5 +121,6 @@ int intel_pasid_setup_nested(struct intel_iommu *iommu,
struct dmar_domain *domain, int addr_width);
void intel_pasid_tear_down_entry(struct intel_iommu *iommu,
struct device *dev, int pasid);
int vcmd_alloc_pasid(struct intel_iommu *iommu, unsigned int *pasid);
void vcmd_free_pasid(struct intel_iommu *iommu, unsigned int pasid);
#endif /* __INTEL_PASID_H */

1
include/linux/intel-iommu.h
View File

@ -169,6 +169,7 @@
#define ecap_smpwc(e) (((e) >> 48) & 0x1)
#define ecap_flts(e) (((e) >> 47) & 0x1)
#define ecap_slts(e) (((e) >> 46) & 0x1)
#define ecap_vcs(e) (((e) >> 44) & 0x1)
#define ecap_smts(e) (((e) >> 43) & 0x1)
#define ecap_dit(e) ((e >> 41) & 0x1)
#define ecap_pasid(e) ((e >> 40) & 0x1)