[RFC PATCH 11/21] iommu/amd: Introduce Reset vMMIO Command

[Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>]

Introduce new IOMMU commands for vIOMMU for resetting
virtualized MMIO registers of a particular guest.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 drivers/iommu/amd/amd_iommu_types.h |  1 +
 drivers/iommu/amd/iommu.c           | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/drivers/iommu/amd/amd_iommu_types.h b/drivers/iommu/amd/amd_iommu_types.h
index d832e0c36a21..aa16a7079b5c 100644
--- a/drivers/iommu/amd/amd_iommu_types.h
+++ b/drivers/iommu/amd/amd_iommu_types.h
@@ -200,6 +200,7 @@
 #define CMD_INV_IRT		0x05
 #define CMD_COMPLETE_PPR	0x07
 #define CMD_INV_ALL		0x08
+#define CMD_RESET_VMMIO		0x0A
 
 #define CMD_COMPL_WAIT_STORE_MASK	0x01
 #define CMD_COMPL_WAIT_INT_MASK		0x02
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index efced59ba8a5..b5c62bc8249c 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1133,6 +1133,18 @@ static void build_inv_irt(struct iommu_cmd *cmd, u16 devid)
 	CMD_SET_TYPE(cmd, CMD_INV_IRT);
 }
 
+static void build_reset_vmmio(struct iommu_cmd *cmd, u16 guestId,
+			      bool vcmd, bool all)
+{
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->data[0] = guestId;
+	if (all)
+		cmd->data[0] |= (1 << 28);
+	if (vcmd)
+		cmd->data[0] |= (1 << 31);
+	CMD_SET_TYPE(cmd, CMD_RESET_VMMIO);
+}
+
 /*
  * Writes the command to the IOMMUs command buffer and informs the
  * hardware about the new command.
@@ -1315,6 +1327,16 @@ void iommu_flush_all_caches(struct amd_iommu *iommu)
 	}
 }
 
+void iommu_reset_vmmio(struct amd_iommu *iommu, u16 guestId)
+{
+	struct iommu_cmd cmd;
+
+	build_reset_vmmio(&cmd, guestId, 1, 1);
+
+	iommu_queue_command(iommu, &cmd);
+	iommu_completion_wait(iommu);
+}
+
 /*
  * Command send function for flushing on-device TLB
  */
-- 
2.34.1