[PATCH] AMD/IOMMU: drop remaining guest-IOMMU bits too

[Jan Beulich <jbeulich@xxxxxxxx>]

With a02174c6c885 ("amd/iommu: clean up unused guest iommu related
functions") having removed the sole place where d->g_iommu would be set
to non-NULL, guest_iommu_add_ppr_log() will unconditionally bail the
latest from its 2nd if(). With it dropped, all other stuff in the file
is unused, too. Delete iommu_guest.c altogether.

Further delete struct guest{_buffer,_dev_table,_iommu{,_msi}} as well as
struct mmio_reg for being unused with the unused g_iommu also dropped
from struct arch_iommu.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
I wasn't sure how far to further go with removing the body of
parse_ppr_log_entry(), or perhaps even the entire function, and then
further up to all PPR logging code. Hence why for now I've merely
commented out the function call into the file being deleted (which of
course Misra isn't going to like). Thoughts / suggestions?

I further wonder whether set_iommu_guest_translation_control() should
have been invoked independent of guest-IOMMU actually being enabled. IOW
that may want purging, too. Along these lines iommuv2_enabled may also
want dropping, for not having any consumer left. Much like has_viommu()
and then also {XEN_,}X86_EMU_IOMMU, i.e. going as far as affecting the
public interface.

--- a/xen/arch/x86/include/asm/iommu.h
+++ b/xen/arch/x86/include/asm/iommu.h
@@ -52,7 +52,6 @@ struct arch_iommu
         struct {
             unsigned int paging_mode;
             struct page_info *root_table;
-            struct guest_iommu *g_iommu;
         } amd;
     };
 };
--- a/xen/drivers/passthrough/amd/Makefile
+++ b/xen/drivers/passthrough/amd/Makefile
@@ -5,4 +5,3 @@ obj-y += pci_amd_iommu.o
 obj-bin-y += iommu_acpi.init.o
 obj-y += iommu_intr.o
 obj-y += iommu_cmd.o
-obj-$(CONFIG_HVM) += iommu_guest.o
--- a/xen/drivers/passthrough/amd/iommu.h
+++ b/xen/drivers/passthrough/amd/iommu.h
@@ -145,57 +145,6 @@ int iterate_ivrs_entries(int (*handler)(
                                         struct ivrs_mappings *map,
                                         uint16_t bdf));
 
-/* iommu tables in guest space */
-struct mmio_reg {
-    uint32_t    lo;
-    uint32_t    hi;
-};
-
-struct guest_dev_table {
-    struct mmio_reg         reg_base;
-    uint32_t                size;
-};
-
-struct guest_buffer {
-    struct mmio_reg         reg_base;
-    struct mmio_reg         reg_tail;
-    struct mmio_reg         reg_head;
-    uint32_t                size;
-};
-
-struct guest_iommu_msi {
-    uint8_t                 vector;
-    uint8_t                 dest;
-    uint8_t                 dest_mode;
-    uint8_t                 delivery_mode;
-    uint8_t                 trig_mode;
-};
-
-/* virtual IOMMU structure */
-struct guest_iommu {
-
-    struct domain          *domain;
-    spinlock_t              lock;
-    bool                    enabled;
-
-    struct guest_dev_table  dev_table;
-    struct guest_buffer     cmd_buffer;
-    struct guest_buffer     event_log;
-    struct guest_buffer     ppr_log;
-
-    struct tasklet          cmd_buffer_tasklet;
-
-    uint64_t                mmio_base;             /* MMIO base address */
-
-    /* MMIO regs */
-    union amd_iommu_control reg_ctrl;              /* MMIO offset 0018h */
-    struct mmio_reg         reg_status;            /* MMIO offset 2020h */
-    union amd_iommu_ext_features reg_ext_feature;  /* MMIO offset 0030h */
-
-    /* guest interrupt settings */
-    struct guest_iommu_msi  msi;
-};
-
 extern bool iommuv2_enabled;
 
 struct acpi_ivrs_hardware;
@@ -344,13 +293,6 @@ void cf_check amd_iommu_resume(void);
 int __must_check cf_check amd_iommu_suspend(void);
 void cf_check amd_iommu_crash_shutdown(void);
 
-/* guest iommu support */
-#ifdef CONFIG_HVM
-void guest_iommu_add_ppr_log(struct domain *d, uint32_t entry[]);
-#else
-static inline void guest_iommu_add_ppr_log(struct domain *d, uint32_t entry[]) 
{}
-#endif
-
 static inline u32 get_field_from_reg_u32(u32 reg_value, u32 mask, u32 shift)
 {
     u32 field;
--- a/xen/drivers/passthrough/amd/iommu_guest.c
+++ /dev/null
@@ -1,120 +0,0 @@
-/*
- * Copyright (C) 2011 Advanced Micro Devices, Inc.
- * Author: Wei Wang <wei.wang2@xxxxxxx>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <asm/p2m.h>
-
-#include "iommu.h"
-
-#define reg_to_u64(reg) (((uint64_t)reg.hi << 32) | reg.lo )
-
-static uint16_t get_guest_bdf(struct domain *d, uint16_t machine_bdf)
-{
-    return machine_bdf;
-}
-
-static inline struct guest_iommu *domain_iommu(struct domain *d)
-{
-    return dom_iommu(d)->arch.amd.g_iommu;
-}
-
-static unsigned long get_gfn_from_base_reg(uint64_t base_raw)
-{
-    base_raw &= PADDR_MASK;
-    ASSERT ( base_raw != 0 );
-    return base_raw >> PAGE_SHIFT;
-}
-
-static void guest_iommu_deliver_msi(struct domain *d)
-{
-    uint8_t vector, dest, dest_mode, delivery_mode, trig_mode;
-    struct guest_iommu *iommu = domain_iommu(d);
-
-    vector = iommu->msi.vector;
-    dest = iommu->msi.dest;
-    dest_mode = iommu->msi.dest_mode;
-    delivery_mode = iommu->msi.delivery_mode;
-    trig_mode = iommu->msi.trig_mode;
-
-    vmsi_deliver(d, vector, dest, dest_mode, delivery_mode, trig_mode);
-}
-
-static unsigned long guest_iommu_get_table_mfn(struct domain *d,
-                                               uint64_t base_raw,
-                                               unsigned int pos)
-{
-    unsigned long idx, gfn, mfn;
-    p2m_type_t p2mt;
-
-    gfn = get_gfn_from_base_reg(base_raw);
-    idx = pos >> PAGE_SHIFT;
-
-    mfn = mfn_x(get_gfn(d, gfn + idx, &p2mt));
-    put_gfn(d, gfn);
-
-    return mfn;
-}
-
-void guest_iommu_add_ppr_log(struct domain *d, u32 entry[])
-{
-    uint16_t gdev_id;
-    unsigned long mfn, tail, head;
-    ppr_entry_t *log;
-    struct guest_iommu *iommu;
-
-    if ( !is_hvm_domain(d) )
-        return;
-
-    iommu = domain_iommu(d);
-    if ( !iommu )
-        return;
-
-    tail = iommu->ppr_log.reg_tail.lo;
-    head = iommu->ppr_log.reg_head.lo;
-
-    if ( tail >= iommu->ppr_log.size || head >= iommu->ppr_log.size )
-    {
-        AMD_IOMMU_DEBUG("Error: guest iommu ppr log overflows\n");
-        iommu->enabled = 0;
-        return;
-    }
-
-    mfn = guest_iommu_get_table_mfn(d, reg_to_u64(iommu->ppr_log.reg_base),
-                                    tail);
-    ASSERT(mfn_valid(_mfn(mfn)));
-
-    log = map_domain_page(_mfn(mfn)) + (tail & ~PAGE_MASK);
-
-    /* Convert physical device id back into virtual device id */
-    gdev_id = get_guest_bdf(d, iommu_get_devid_from_cmd(entry[0]));
-    iommu_set_devid_to_cmd(&entry[0], gdev_id);
-
-    memcpy(log, entry, sizeof(ppr_entry_t));
-
-    /* Now shift ppr log tail pointer */
-    tail += sizeof(ppr_entry_t);
-    if ( tail >= iommu->ppr_log.size )
-    {
-        tail = 0;
-        iommu->reg_status.lo |= IOMMU_STATUS_PPR_LOG_OVERFLOW;
-    }
-
-    iommu->ppr_log.reg_tail.lo = tail;
-    unmap_domain_page(log);
-
-    guest_iommu_deliver_msi(d);
-}
--- a/xen/drivers/passthrough/amd/iommu_init.c
+++ b/xen/drivers/passthrough/amd/iommu_init.c
@@ -646,7 +646,7 @@ static void cf_check parse_ppr_log_entry
     pcidevs_unlock();
 
     if ( pdev )
-        guest_iommu_add_ppr_log(pdev->domain, entry);
+        /* guest_iommu_add_ppr_log(pdev->domain, entry) */;
 }
 
 static void iommu_check_ppr_log(struct amd_iommu *iommu)