[PATCH v11 0/3] iommu: add rmrr Xen command line option

[PATCH v11 0/3] iommu: add rmrr Xen command line option

[elena.ufimtseva]

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

Its being a while since the last v10. There are subtle changes and fewer
patches in the series and will be nice to move it out of my way.
Please review and comment.

Add Xen command line option rmrr to specify RMRR                                
regions for devices that are not defined in ACPI thus                           
causing IO Page Fault while booting dom0 in PVH mode.                           
These additional regions will be added to the list of                           
RMRR regions parsed from ACPI.

Changes in v11:
 - changed macro to print extra RMRR ranges and added argument macro;
 - fixed the overlapping check if condition error;
 - fixed the loop exit condition when checking pfn in RMRR region;

Changes in v10:
 - incorporate patch 'dmar: device scope mem leak fix' as series requires it;
 - move patch 'pci: add PCI_SBDF and PCI_SEG macros' close to the last patch which uses it;
 
Changes in v9:
 - skip to next RMRR region if current overlaps with any in acpi_rmrr_units;
 - fix typos in commit messages;
 - remove clean up chages introduced by mistake in v8;  

Elena Ufimtseva (3):
  iommu VT-d: separate rmrr addition function
  pci: add wrapper for parse_pci
  iommu: add rmrr Xen command line option for extra rmrrs

Changes in v8:                                                                  
 - removed bogus debug in patch 1 with non-functional changes;                  
 - changed PRI_RMRRL macro for formatting to reflect the fact that two arguments
   are used, so make it PRI_RMRR(s,e) for formatting inclusive RMRR range;      
   'L' is also removed from macro name, which meant to server as a type of arguments (%lx);
 - added overlapping check with RMRRs from ACPI;                                
 - added check based on paddr_bits for pfn's in extra RMRR range (not sure if   
   its redundant with mfn_valid);                                               
 - addressed while loop exit condition in extra RMRRs parser;

 docs/misc/xen-command-line.markdown |  13 ++
 xen/drivers/passthrough/vtd/dmar.c  | 322 +++++++++++++++++++++++++++++-------
 xen/drivers/pci/pci.c               |  11 ++
 xen/include/xen/pci.h               |   3 +
 4 files changed, 287 insertions(+), 62 deletions(-)

-- 
2.1.4

[PATCH v11 1/3] iommu VT-d: separate rmrr addition function

[elena.ufimtseva]

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

In preparation for auxiliary RMRR data provided on Xen
command line, make RMRR adding a separate function.
Also free memery for rmrr device scope in error path.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>                     
---
 xen/drivers/passthrough/vtd/dmar.c | 126 +++++++++++++++++++------------------
 1 file changed, 65 insertions(+), 61 deletions(-)

diff --git a/xen/drivers/passthrough/vtd/dmar.c b/xen/drivers/passthrough/vtd/dmar.c
index 7cad593..ced3239 100644
--- a/xen/drivers/passthrough/vtd/dmar.c
+++ b/xen/drivers/passthrough/vtd/dmar.c
@@ -583,6 +583,68 @@ out:
     return ret;
 }
 
+static int register_one_rmrr(struct acpi_rmrr_unit *rmrru)
+{
+    bool_t ignore = 0;
+    unsigned int i = 0;
+    int ret = 0;
+
+    /* Skip checking if segment is not accessible yet. */
+    if ( !pci_known_segment(rmrru->segment) )
+        i = UINT_MAX;
+
+    for ( ; i < rmrru->scope.devices_cnt; i++ )
+    {
+        u8 b = PCI_BUS(rmrru->scope.devices[i]);
+        u8 d = PCI_SLOT(rmrru->scope.devices[i]);
+        u8 f = PCI_FUNC(rmrru->scope.devices[i]);
+
+        if ( pci_device_detect(rmrru->segment, b, d, f) == 0 )
+        {
+            dprintk(XENLOG_WARNING VTDPREFIX,
+                    " Non-existent device (%04x:%02x:%02x.%u) is reported"
+                    " in RMRR (%"PRIx64", %"PRIx64")'s scope!\n",
+                    rmrru->segment, b, d, f,
+                    rmrru->base_address, rmrru->end_address);
+            ignore = 1;
+        }
+        else
+        {
+            ignore = 0;
+            break;
+        }
+    }
+
+    if ( ignore )
+    {
+        dprintk(XENLOG_WARNING VTDPREFIX,
+                "  Ignore the RMRR (%"PRIx64", %"PRIx64") due to "
+                "devices under its scope are not PCI discoverable!\n",
+            rmrru->base_address, rmrru->end_address);
+        scope_devices_free(&rmrru->scope);
+        xfree(rmrru);
+    }
+    else if ( rmrru->base_address > rmrru->end_address )
+    {
+        dprintk(XENLOG_WARNING VTDPREFIX,
+                "  The RMRR (%"PRIx64", %"PRIx64") is incorrect!\n",
+                rmrru->base_address, rmrru->end_address);
+        scope_devices_free(&rmrru->scope);
+        xfree(rmrru);
+        ret = -EFAULT;
+    }
+    else
+    {
+        if ( iommu_verbose )
+            dprintk(VTDPREFIX,
+                    "  RMRR region: base_addr %"PRIx64" end_address %"PRIx64"\n",
+                    rmrru->base_address, rmrru->end_address);
+        acpi_register_rmrr_unit(rmrru);
+    }
+
+    return ret;
+}
+
 static int __init
 acpi_parse_one_rmrr(struct acpi_dmar_header *header)
 {
@@ -633,68 +695,10 @@ acpi_parse_one_rmrr(struct acpi_dmar_header *header)
     ret = acpi_parse_dev_scope(dev_scope_start, dev_scope_end,
                                &rmrru->scope, RMRR_TYPE, rmrr->segment);
 
-    if ( ret || (rmrru->scope.devices_cnt == 0) )
-        xfree(rmrru);
+    if ( !ret && (rmrru->scope.devices_cnt != 0) )
+        register_one_rmrr(rmrru);
     else
-    {
-        u8 b, d, f;
-        bool_t ignore = 0;
-        unsigned int i = 0;
-
-        /* Skip checking if segment is not accessible yet. */
-        if ( !pci_known_segment(rmrr->segment) )
-            i = UINT_MAX;
-
-        for ( ; i < rmrru->scope.devices_cnt; i++ )
-        {
-            b = PCI_BUS(rmrru->scope.devices[i]);
-            d = PCI_SLOT(rmrru->scope.devices[i]);
-            f = PCI_FUNC(rmrru->scope.devices[i]);
-
-            if ( !pci_device_detect(rmrr->segment, b, d, f) )
-            {
-                dprintk(XENLOG_WARNING VTDPREFIX,
-                        " Non-existent device (%04x:%02x:%02x.%u) is reported"
-                        " in RMRR (%"PRIx64", %"PRIx64")'s scope!\n",
-                        rmrr->segment, b, d, f,
-                        rmrru->base_address, rmrru->end_address);
-                ignore = 1;
-            }
-            else
-            {
-                ignore = 0;
-                break;
-            }
-        }
-
-        if ( ignore )
-        {
-            dprintk(XENLOG_WARNING VTDPREFIX,
-                "  Ignore the RMRR (%"PRIx64", %"PRIx64") due to "
-                "devices under its scope are not PCI discoverable!\n",
-                rmrru->base_address, rmrru->end_address);
-            scope_devices_free(&rmrru->scope);
-            xfree(rmrru);
-        }
-        else if ( base_addr > end_addr )
-        {
-            dprintk(XENLOG_WARNING VTDPREFIX,
-                "  The RMRR (%"PRIx64", %"PRIx64") is incorrect!\n",
-                rmrru->base_address, rmrru->end_address);
-            scope_devices_free(&rmrru->scope);
-            xfree(rmrru);
-            ret = -EFAULT;
-        }
-        else
-        {
-            if ( iommu_verbose )
-                dprintk(VTDPREFIX,
-                        "  RMRR region: base_addr %"PRIx64
-                        " end_address %"PRIx64"\n",
-                        rmrru->base_address, rmrru->end_address);
-            acpi_register_rmrr_unit(rmrru);
-        }
-    }
+        xfree(rmrru);
 
     return ret;
 }
-- 
2.1.4

[PATCH v11 2/3] pci: add wrapper for parse_pci

[elena.ufimtseva]

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

For sbdf's parsing in RMRR command line add __parse_pci with additional
parameter def_seg. __parse_pci will help to identify if segment was
found in string being parsed or default segment was used.
Make a wrapper parse_pci so the rest of the callers are not affected.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
 xen/drivers/pci/pci.c | 11 +++++++++++
 xen/include/xen/pci.h |  3 +++
 2 files changed, 14 insertions(+)

diff --git a/xen/drivers/pci/pci.c b/xen/drivers/pci/pci.c
index ca07ed0..788a356 100644
--- a/xen/drivers/pci/pci.c
+++ b/xen/drivers/pci/pci.c
@@ -119,11 +119,21 @@ const char *__init parse_pci(const char *s, unsigned int *seg_p,
                              unsigned int *bus_p, unsigned int *dev_p,
                              unsigned int *func_p)
 {
+    bool_t def_seg;
+
+    return __parse_pci(s, seg_p, bus_p, dev_p, func_p, &def_seg);
+}
+
+const char *__init __parse_pci(const char *s, unsigned int *seg_p,
+                             unsigned int *bus_p, unsigned int *dev_p,
+                             unsigned int *func_p, bool_t *def_seg)
+{
     unsigned long seg = simple_strtoul(s, &s, 16), bus, dev, func;
 
     if ( *s != ':' )
         return NULL;
     bus = simple_strtoul(s + 1, &s, 16);
+    *def_seg = 0;
     if ( *s == ':' )
         dev = simple_strtoul(s + 1, &s, 16);
     else
@@ -131,6 +141,7 @@ const char *__init parse_pci(const char *s, unsigned int *seg_p,
         dev = bus;
         bus = seg;
         seg = 0;
+        *def_seg = 1;
     }
     if ( func_p )
     {
diff --git a/xen/include/xen/pci.h b/xen/include/xen/pci.h
index a5aef55..a7b62a4 100644
--- a/xen/include/xen/pci.h
+++ b/xen/include/xen/pci.h
@@ -151,6 +151,9 @@ int pci_find_ext_capability(int seg, int bus, int devfn, int cap);
 int pci_find_next_ext_capability(int seg, int bus, int devfn, int pos, int cap);
 const char *parse_pci(const char *, unsigned int *seg, unsigned int *bus,
                       unsigned int *dev, unsigned int *func);
+const char *__parse_pci(const char *, unsigned int *seg, unsigned int *bus,
+                      unsigned int *dev, unsigned int *func, bool_t *def_seg);
+
 
 bool_t pcie_aer_get_firmware_first(const struct pci_dev *);
 
-- 
2.1.4

[PATCH v11 3/3] iommu: add rmrr Xen command line option for extra rmrrs

[elena.ufimtseva]

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

On some platforms RMRR regions may be not specified in ACPI and thus will not
be mapped 1:1 in dom0. This causes IO Page Faults and prevents dom0 from booting
in PVH mode. New Xen command line option rmrr allows to specify such devices and
memory regions. These regions are added to the list of RMRR defined in ACPI if
the device is present in system. As a result, additional RMRRs will be mapped 1:1 in dom0 with correct permissions.

Mentioned above problems were discovered during PVH work with ThinkCentre M
and Dell 5600T. No official documentation was found so far in regards to what
devices and why cause this. Experiments show that ThinkCentre M USB devices
with enabled debug port generate DMA read transactions to the regions of
memory marked reserved in host e820 map.

For Dell 5600T the device and faulting addresses are not found yet.
For detailed history of the discussion please check following threads:
http://lists.Xen.org/archives/html/xen-devel/2015-02/msg01724.html
http://lists.Xen.org/archives/html/xen-devel/2015-01/msg02513.html

Format for rmrr Xen command line option:
rmrr=start<-end>=[s1]bdf1[,[s1]bdf2[,...]];start<-end>=[s2]bdf1[,[s2]bdf2[,...]]
If grub2 used and multiple ranges are specified, ';' should be
quoted/escaped, refer to grub2 manual for more information.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
---
 docs/misc/xen-command-line.markdown |  13 +++
 xen/drivers/passthrough/vtd/dmar.c  | 196 +++++++++++++++++++++++++++++++++++-
 2 files changed, 208 insertions(+), 1 deletion(-)

diff --git a/docs/misc/xen-command-line.markdown b/docs/misc/xen-command-line.markdown
index 416e559..92c69ea 100644
--- a/docs/misc/xen-command-line.markdown
+++ b/docs/misc/xen-command-line.markdown
@@ -1240,6 +1240,19 @@ Specify the host reboot method.
 'efi' instructs Xen to reboot using the EFI reboot call (in EFI mode by
  default it will use that method first).
 
+### rmrr
+> '= start<-end>=[s1]bdf1[,[s1]bdf2[,...]];start<-end>=[s2]bdf1[,[s2]bdf2[,...]]
+
+Define RMRR units that are missing from ACPI table along with device they
+belong to and use them for 1:1 mapping. End addresses can be omitted and one
+page will be mapped. The ranges are inclusive when start and end are specified.
+If segment of the first device is not specified, segment zero will be used.
+If other segments are not specified, first device segment will be used.
+If a segment is specified for other than the first device and it does not match
+the one specified for the first one, an error will be reported.
+Note: grub2 requires to escape or use quotations if special characters are used,
+namely ';', refer to the grub2 documentation if multiple ranges are specified.
+
 ### ro-hpet
 > `= <boolean>`
 
diff --git a/xen/drivers/passthrough/vtd/dmar.c b/xen/drivers/passthrough/vtd/dmar.c
index ced3239..8cbed88 100644
--- a/xen/drivers/passthrough/vtd/dmar.c
+++ b/xen/drivers/passthrough/vtd/dmar.c
@@ -867,6 +867,132 @@ out:
     return ret;
 }
 
+#define MAX_EXTRA_RMRR_PAGES 16
+#define MAX_EXTRA_RMRR 10
+
+/* RMRR units derived from command line rmrr option. */
+#define MAX_EXTRA_RMRR_DEV 20
+struct extra_rmrr_unit {
+    struct list_head list;
+    unsigned long base_pfn, end_pfn;
+    unsigned int dev_count;
+    u32 sbdf[MAX_EXTRA_RMRR_DEV];
+};
+
+static __initdata unsigned int nr_rmrr;
+static struct __initdata extra_rmrr_unit extra_rmrr_units[MAX_EXTRA_RMRR];
+
+/* Macro for RMRR inclusive range formatting. */
+#define ERMRRU_FMT "[%lx-%lx]"
+#define ERMRRU_ARG(eru) eru.base_pfn, eru.end_pfn
+
+static void __init add_extra_rmrr(void)
+{
+    struct acpi_rmrr_unit *acpi_rmrr;
+    struct acpi_rmrr_unit *rmrru;
+    unsigned int dev, seg, i;
+    unsigned long pfn;
+    bool_t overlap;
+
+    for ( i = 0; i < nr_rmrr; i++ )
+    {
+        if ( extra_rmrr_units[i].base_pfn > extra_rmrr_units[i].end_pfn )
+        {
+            printk(XENLOG_ERR VTDPREFIX
+                   "Invalid RMRR Range "ERMRRU_FMT"\n",
+                   ERMRRU_ARG(extra_rmrr_units[i]));
+            continue;
+        }
+
+        if ( extra_rmrr_units[i].end_pfn - extra_rmrr_units[i].base_pfn >=
+             MAX_EXTRA_RMRR_PAGES )
+        {
+            printk(XENLOG_ERR VTDPREFIX
+                   "RMRR range "ERMRRU_FMT" exceeds "__stringify(MAX_EXTRA_RMRR_PAGES)" pages\n",
+                   ERMRRU_ARG(extra_rmrr_units[i]));
+            continue;
+        }
+
+        overlap = 0;
+        list_for_each_entry(rmrru, &acpi_rmrr_units, list)
+        {
+            if ( pfn_to_paddr(extra_rmrr_units[i].base_pfn ) < rmrru->end_address &&
+                 rmrru->base_address < pfn_to_paddr(extra_rmrr_units[i].end_pfn + 1) )
+            {
+                printk(XENLOG_ERR VTDPREFIX
+                       "Overlapping RMRRs: "ERMRRU_FMT" and [%lx - %lx]\n",
+                       ERMRRU_ARG(extra_rmrr_units[i]),
+                       paddr_to_pfn(rmrru->base_address),
+                       paddr_to_pfn(rmrru->end_address));
+                overlap = 1;
+                break;
+            }
+        }
+        /* Dont add overlapping RMRR */
+        if ( overlap )
+            continue;
+
+        pfn = extra_rmrr_units[i].base_pfn;
+        do
+        {
+            if ( !mfn_valid(pfn) || (pfn >> (paddr_bits - PAGE_SHIFT)) )
+            {
+                printk(XENLOG_ERR VTDPREFIX
+                       "Invalid pfn in RMRR range "ERMRRU_FMT"\n",
+                       ERMRRU_ARG(extra_rmrr_units[i]));
+            break;
+            }
+
+        } while ( pfn++ < extra_rmrr_units[i].end_pfn );
+
+        /* Invalid pfn in range as the loop ended before end_pfn was reached. */
+        if ( pfn <= extra_rmrr_units[i].end_pfn )
+            continue;
+
+        acpi_rmrr = xzalloc(struct acpi_rmrr_unit);
+        if ( !acpi_rmrr )
+            return;
+
+        acpi_rmrr->scope.devices = xmalloc_array(u16,
+                                                 extra_rmrr_units[i].dev_count);
+        if ( !acpi_rmrr->scope.devices )
+        {
+            xfree(acpi_rmrr);
+            return;
+        }
+
+        seg = 0;
+        for ( dev = 0; dev < extra_rmrr_units[i].dev_count; dev++ )
+        {
+            acpi_rmrr->scope.devices[dev] = extra_rmrr_units[i].sbdf[dev];
+            seg = seg | PCI_SEG(extra_rmrr_units[i].sbdf[dev]);
+        }
+        if ( seg != PCI_SEG(extra_rmrr_units[i].sbdf[0]) )
+        {
+            printk(XENLOG_ERR VTDPREFIX
+                   "Segments are not equal for RMRR range "ERMRRU_FMT"\n",
+                   ERMRRU_ARG(extra_rmrr_units[i]));
+            scope_devices_free(&acpi_rmrr->scope);
+            xfree(acpi_rmrr);
+            continue;
+        }
+
+        acpi_rmrr->segment = seg;
+        acpi_rmrr->base_address = pfn_to_paddr(extra_rmrr_units[i].base_pfn);
+        acpi_rmrr->end_address = pfn_to_paddr(extra_rmrr_units[i].end_pfn + 1);
+        acpi_rmrr->scope.devices_cnt = extra_rmrr_units[i].dev_count;
+
+        if ( register_one_rmrr(acpi_rmrr) )
+        {
+            printk(XENLOG_ERR VTDPREFIX
+                   "Could not register RMMR range "ERMRRU_FMT"\n",
+                   ERMRRU_ARG(extra_rmrr_units[i]));
+            scope_devices_free(&acpi_rmrr->scope);
+            xfree(acpi_rmrr);
+        }
+    }
+}
+
 #include <asm/tboot.h>
 /* ACPI tables may not be DMA protected by tboot, so use DMAR copy */
 /* SINIT saved in SinitMleData in TXT heap (which is DMA protected) */
@@ -876,6 +1002,7 @@ int __init acpi_dmar_init(void)
 {
     acpi_physical_address dmar_addr;
     acpi_native_uint dmar_len;
+    int ret;
 
     if ( ACPI_SUCCESS(acpi_get_table_phys(ACPI_SIG_DMAR, 0,
                                           &dmar_addr, &dmar_len)) )
@@ -886,7 +1013,10 @@ int __init acpi_dmar_init(void)
         dmar_table = __va(dmar_addr);
     }
 
-    return parse_dmar_table(acpi_parse_dmar);
+    ret = parse_dmar_table(acpi_parse_dmar);
+    add_extra_rmrr();
+
+    return ret;
 }
 
 void acpi_dmar_reinstate(void)
@@ -945,3 +1075,67 @@ int intel_iommu_get_reserved_device_memory(iommu_grdm_t *func, void *ctxt)
 
     return 0;
 }
+
+/*
+ * Parse rmrr Xen command line options and add parsed device and region into
+ * acpi_rmrr_unit list to mapped as RMRRs parsed from ACPI.
+ * Format:
+ * rmrr=start<-end>=[s1]bdf1[,[s1]bdf2[,...]];start<-end>=[s2]bdf1[,[s2]bdf2[,...]]
+ * If the segment of the first device is not specified, segment zero will be used.
+ * If other segments are not specified, first device segment will be used.
+ * If a segment is specified for other than the first device and it does not match
+ * the one specified for the first one, an error will be reported.
+ */
+static void __init parse_rmrr_param(const char *str)
+{
+    const char *s = str, *cur, *stmp;
+    unsigned int seg, bus, dev, func;
+    unsigned long start, end;
+
+    do {
+        start = simple_strtoul(cur = s, &s, 0);
+        if ( cur == s )
+            break;
+
+        if ( *s == '-' )
+        {
+            end = simple_strtoul(cur = s + 1, &s, 0);
+            if ( cur == s )
+                break;
+        }
+        else
+            end = start;
+
+        extra_rmrr_units[nr_rmrr].base_pfn = start;
+        extra_rmrr_units[nr_rmrr].end_pfn = end;
+        extra_rmrr_units[nr_rmrr].dev_count = 0;
+
+        if ( *s != '=' )
+            continue;
+
+        do {
+            bool_t default_segment = 0;
+
+            if ( *s == ';' )
+                break;
+            stmp = __parse_pci(s + 1, &seg, &bus, &dev, &func, &default_segment);
+            if ( !stmp )
+                break;
+
+            /* Not specified segment will be replaced with one from first device. */
+            if ( extra_rmrr_units[nr_rmrr].dev_count && default_segment )
+                seg = PCI_SEG(extra_rmrr_units[nr_rmrr].sbdf[0]);
+
+            /* Keep sbdf's even if they differ and later report an error. */
+            extra_rmrr_units[nr_rmrr].sbdf[extra_rmrr_units[nr_rmrr].dev_count]                                             = PCI_SBDF(seg, bus, dev, func);
+            extra_rmrr_units[nr_rmrr].dev_count++;
+            s = stmp;
+        } while ( *s == ',' &&
+                  extra_rmrr_units[nr_rmrr].dev_count < MAX_EXTRA_RMRR_DEV );
+
+        if ( extra_rmrr_units[nr_rmrr].dev_count )
+            nr_rmrr++;
+
+    } while ( *s++ == ';' && nr_rmrr < MAX_EXTRA_RMRR );
+}
+custom_param("rmrr", parse_rmrr_param);
-- 
2.1.4

Re: [PATCH v11 1/3] iommu VT-d: separate rmrr addition function

[Jan Beulich]

>>> On 22.10.15 at 19:13, <elena.ufimtseva@oracle.com> wrote:
> --- a/xen/drivers/passthrough/vtd/dmar.c
> +++ b/xen/drivers/passthrough/vtd/dmar.c
> @@ -583,6 +583,68 @@ out:
>      return ret;
>  }
>  
> +static int register_one_rmrr(struct acpi_rmrr_unit *rmrru)
> +{
> +    bool_t ignore = 0;
> +    unsigned int i = 0;
> +    int ret = 0;
> +
> +    /* Skip checking if segment is not accessible yet. */
> +    if ( !pci_known_segment(rmrru->segment) )
> +        i = UINT_MAX;
> +
> +    for ( ; i < rmrru->scope.devices_cnt; i++ )
> +    {
> +        u8 b = PCI_BUS(rmrru->scope.devices[i]);
> +        u8 d = PCI_SLOT(rmrru->scope.devices[i]);
> +        u8 f = PCI_FUNC(rmrru->scope.devices[i]);
> +
> +        if ( pci_device_detect(rmrru->segment, b, d, f) == 0 )
> +        {
> +            dprintk(XENLOG_WARNING VTDPREFIX,
> +                    " Non-existent device (%04x:%02x:%02x.%u) is reported"
> +                    " in RMRR (%"PRIx64", %"PRIx64")'s scope!\n",
> +                    rmrru->segment, b, d, f,
> +                    rmrru->base_address, rmrru->end_address);
> +            ignore = 1;
> +        }
> +        else
> +        {
> +            ignore = 0;
> +            break;
> +        }
> +    }
> +
> +    if ( ignore )
> +    {
> +        dprintk(XENLOG_WARNING VTDPREFIX,
> +                "  Ignore the RMRR (%"PRIx64", %"PRIx64") due to "
> +                "devices under its scope are not PCI discoverable!\n",
> +            rmrru->base_address, rmrru->end_address);

Broken indentation, but since everything else looks okay this can of
course be fixed up while committing, provided we can get a VT-d
maintainer ack.

Jan

Re: [PATCH v11 3/3] iommu: add rmrr Xen command line option for extra rmrrs

[Jan Beulich]

>>> On 22.10.15 at 19:13, <elena.ufimtseva@oracle.com> wrote:
> From: Elena Ufimtseva <elena.ufimtseva@oracle.com>
> 
> On some platforms RMRR regions may be not specified in ACPI and thus will not
> be mapped 1:1 in dom0.

I think this may be misleading to readers: It sounds as if there was
the option for RMRRs to not be specified in ACPI tables, while in
fact this is a firmware bug. How about "On some platforms firmware
fails to specify RMRR regions may in ACPI tables, and thus those
regions will not be mapped in dom0 or guests the respective device(s)
get passed through to"?

> +static void __init add_extra_rmrr(void)
> +{
> +    struct acpi_rmrr_unit *acpi_rmrr;
> +    struct acpi_rmrr_unit *rmrru;
> +    unsigned int dev, seg, i;
> +    unsigned long pfn;
> +    bool_t overlap;
> +
> +    for ( i = 0; i < nr_rmrr; i++ )
> +    {
> +        if ( extra_rmrr_units[i].base_pfn > extra_rmrr_units[i].end_pfn )
> +        {
> +            printk(XENLOG_ERR VTDPREFIX
> +                   "Invalid RMRR Range "ERMRRU_FMT"\n",
> +                   ERMRRU_ARG(extra_rmrr_units[i]));
> +            continue;
> +        }
> +
> +        if ( extra_rmrr_units[i].end_pfn - extra_rmrr_units[i].base_pfn >=
> +             MAX_EXTRA_RMRR_PAGES )
> +        {
> +            printk(XENLOG_ERR VTDPREFIX
> +                   "RMRR range "ERMRRU_FMT" exceeds "__stringify(MAX_EXTRA_RMRR_PAGES)" pages\n",
> +                   ERMRRU_ARG(extra_rmrr_units[i]));
> +            continue;
> +        }
> +
> +        overlap = 0;
> +        list_for_each_entry(rmrru, &acpi_rmrr_units, list)
> +        {
> +            if ( pfn_to_paddr(extra_rmrr_units[i].base_pfn ) < rmrru->end_address &&

Stray blank inside the inner parentheses.

> +                 rmrru->base_address < pfn_to_paddr(extra_rmrr_units[i].end_pfn + 1) )
> +            {
> +                printk(XENLOG_ERR VTDPREFIX
> +                       "Overlapping RMRRs: "ERMRRU_FMT" and [%lx - %lx]\n",

ERMRRU_FMT doesn't have any blanks inside the square brackets,
so I'd suggest the other format to nt have them either.

> +                       ERMRRU_ARG(extra_rmrr_units[i]),
> +                       paddr_to_pfn(rmrru->base_address),
> +                       paddr_to_pfn(rmrru->end_address));
> +                overlap = 1;
> +                break;
> +            }
> +        }
> +        /* Dont add overlapping RMRR */

"Don't" and missing full stop.

> +        if ( overlap )
> +            continue;
> +
> +        pfn = extra_rmrr_units[i].base_pfn;
> +        do
> +        {
> +            if ( !mfn_valid(pfn) || (pfn >> (paddr_bits - PAGE_SHIFT)) )

Actually I think the right side is redundant with the max_pfn check
mfn_valid() does.

> +            {
> +                printk(XENLOG_ERR VTDPREFIX
> +                       "Invalid pfn in RMRR range "ERMRRU_FMT"\n",
> +                       ERMRRU_ARG(extra_rmrr_units[i]));
> +            break;

Wrong indentation.

> +            }
> +
> +        } while ( pfn++ < extra_rmrr_units[i].end_pfn );

Stray blank line before the end of the do/while body.

> +
> +        /* Invalid pfn in range as the loop ended before end_pfn was reached. */
> +        if ( pfn <= extra_rmrr_units[i].end_pfn )
> +            continue;
> +
> +        acpi_rmrr = xzalloc(struct acpi_rmrr_unit);
> +        if ( !acpi_rmrr )
> +            return;
> +
> +        acpi_rmrr->scope.devices = xmalloc_array(u16,
> +                                                 extra_rmrr_units[i].dev_count);
> +        if ( !acpi_rmrr->scope.devices )
> +        {
> +            xfree(acpi_rmrr);
> +            return;
> +        }
> +
> +        seg = 0;
> +        for ( dev = 0; dev < extra_rmrr_units[i].dev_count; dev++ )
> +        {
> +            acpi_rmrr->scope.devices[dev] = extra_rmrr_units[i].sbdf[dev];
> +            seg = seg | PCI_SEG(extra_rmrr_units[i].sbdf[dev]);

|=

> +static void __init parse_rmrr_param(const char *str)
> +{
> +    const char *s = str, *cur, *stmp;
> +    unsigned int seg, bus, dev, func;
> +    unsigned long start, end;
> +
> +    do {
> +        start = simple_strtoul(cur = s, &s, 0);
> +        if ( cur == s )
> +            break;
> +
> +        if ( *s == '-' )
> +        {
> +            end = simple_strtoul(cur = s + 1, &s, 0);
> +            if ( cur == s )
> +                break;
> +        }
> +        else
> +            end = start;
> +
> +        extra_rmrr_units[nr_rmrr].base_pfn = start;
> +        extra_rmrr_units[nr_rmrr].end_pfn = end;
> +        extra_rmrr_units[nr_rmrr].dev_count = 0;

The last assignment isn't really needed.

> +        if ( *s != '=' )
> +            continue;
> +
> +        do {
> +            bool_t default_segment = 0;
> +
> +            if ( *s == ';' )
> +                break;

Can this if() ever be true? *s == '=' on the first iteration, and *s == ','
on any subsequent one afaics.

> +            stmp = __parse_pci(s + 1, &seg, &bus, &dev, &func, &default_segment);
> +            if ( !stmp )
> +                break;
> +
> +            /* Not specified segment will be replaced with one from first device. */
> +            if ( extra_rmrr_units[nr_rmrr].dev_count && default_segment )
> +                seg = PCI_SEG(extra_rmrr_units[nr_rmrr].sbdf[0]);
> +
> +            /* Keep sbdf's even if they differ and later report an error. */
> +            extra_rmrr_units[nr_rmrr].sbdf[extra_rmrr_units[nr_rmrr].dev_count]                                             = PCI_SBDF(seg, bus, dev, func);

This line for sure is too long.

Jan

Re: [PATCH v11 3/3] iommu: add rmrr Xen command line option for extra rmrrs

[Elena Ufimtseva]

On Mon, Oct 26, 2015 at 07:38:06AM -0600, Jan Beulich wrote:
> >>> On 22.10.15 at 19:13, <elena.ufimtseva@oracle.com> wrote:
> > From: Elena Ufimtseva <elena.ufimtseva@oracle.com>
> > 
> > On some platforms RMRR regions may be not specified in ACPI and thus will not
> > be mapped 1:1 in dom0.
>

Thanks Jan for review.

> I think this may be misleading to readers: It sounds as if there was
> the option for RMRRs to not be specified in ACPI tables, while in
> fact this is a firmware bug. How about "On some platforms firmware
> fails to specify RMRR regions may in ACPI tables, and thus those
> regions will not be mapped in dom0 or guests the respective device(s)
> get passed through to"?
>
Agree, makes more sense.

> > +static void __init add_extra_rmrr(void)
> > +{
> > +    struct acpi_rmrr_unit *acpi_rmrr;
> > +    struct acpi_rmrr_unit *rmrru;
> > +    unsigned int dev, seg, i;
> > +    unsigned long pfn;
> > +    bool_t overlap;
> > +
> > +    for ( i = 0; i < nr_rmrr; i++ )
> > +    {
> > +        if ( extra_rmrr_units[i].base_pfn > extra_rmrr_units[i].end_pfn )
> > +        {
> > +            printk(XENLOG_ERR VTDPREFIX
> > +                   "Invalid RMRR Range "ERMRRU_FMT"\n",
> > +                   ERMRRU_ARG(extra_rmrr_units[i]));
> > +            continue;
> > +        }
> > +
> > +        if ( extra_rmrr_units[i].end_pfn - extra_rmrr_units[i].base_pfn >=
> > +             MAX_EXTRA_RMRR_PAGES )
> > +        {
> > +            printk(XENLOG_ERR VTDPREFIX
> > +                   "RMRR range "ERMRRU_FMT" exceeds "__stringify(MAX_EXTRA_RMRR_PAGES)" pages\n",
> > +                   ERMRRU_ARG(extra_rmrr_units[i]));
> > +            continue;
> > +        }
> > +
> > +        overlap = 0;
> > +        list_for_each_entry(rmrru, &acpi_rmrr_units, list)
> > +        {
> > +            if ( pfn_to_paddr(extra_rmrr_units[i].base_pfn ) < rmrru->end_address &&
> 
> Stray blank inside the inner parentheses.
> 
> > +                 rmrru->base_address < pfn_to_paddr(extra_rmrr_units[i].end_pfn + 1) )
> > +            {
> > +                printk(XENLOG_ERR VTDPREFIX
> > +                       "Overlapping RMRRs: "ERMRRU_FMT" and [%lx - %lx]\n",
> 
> ERMRRU_FMT doesn't have any blanks inside the square brackets,
> so I'd suggest the other format to nt have them either.
> 
> > +                       ERMRRU_ARG(extra_rmrr_units[i]),
> > +                       paddr_to_pfn(rmrru->base_address),
> > +                       paddr_to_pfn(rmrru->end_address));
> > +                overlap = 1;
> > +                break;
> > +            }
> > +        }
> > +        /* Dont add overlapping RMRR */
> 
> "Don't" and missing full stop.
> 
> > +        if ( overlap )
> > +            continue;
> > +
> > +        pfn = extra_rmrr_units[i].base_pfn;
> > +        do
> > +        {
> > +            if ( !mfn_valid(pfn) || (pfn >> (paddr_bits - PAGE_SHIFT)) )
> 
> Actually I think the right side is redundant with the max_pfn check
> mfn_valid() does.
> 
> > +            {
> > +                printk(XENLOG_ERR VTDPREFIX
> > +                       "Invalid pfn in RMRR range "ERMRRU_FMT"\n",
> > +                       ERMRRU_ARG(extra_rmrr_units[i]));
> > +            break;
> 
> Wrong indentation.
> 
> > +            }
> > +
> > +        } while ( pfn++ < extra_rmrr_units[i].end_pfn );
> 
> Stray blank line before the end of the do/while body.
> 
> > +
> > +        /* Invalid pfn in range as the loop ended before end_pfn was reached. */
> > +        if ( pfn <= extra_rmrr_units[i].end_pfn )
> > +            continue;
> > +
> > +        acpi_rmrr = xzalloc(struct acpi_rmrr_unit);
> > +        if ( !acpi_rmrr )
> > +            return;
> > +
> > +        acpi_rmrr->scope.devices = xmalloc_array(u16,
> > +                                                 extra_rmrr_units[i].dev_count);
> > +        if ( !acpi_rmrr->scope.devices )
> > +        {
> > +            xfree(acpi_rmrr);
> > +            return;
> > +        }
> > +
> > +        seg = 0;
> > +        for ( dev = 0; dev < extra_rmrr_units[i].dev_count; dev++ )
> > +        {
> > +            acpi_rmrr->scope.devices[dev] = extra_rmrr_units[i].sbdf[dev];
> > +            seg = seg | PCI_SEG(extra_rmrr_units[i].sbdf[dev]);
> 
> |=
> 
> > +static void __init parse_rmrr_param(const char *str)
> > +{
> > +    const char *s = str, *cur, *stmp;
> > +    unsigned int seg, bus, dev, func;
> > +    unsigned long start, end;
> > +
> > +    do {
> > +        start = simple_strtoul(cur = s, &s, 0);
> > +        if ( cur == s )
> > +            break;
> > +
> > +        if ( *s == '-' )
> > +        {
> > +            end = simple_strtoul(cur = s + 1, &s, 0);
> > +            if ( cur == s )
> > +                break;
> > +        }
> > +        else
> > +            end = start;
> > +
> > +        extra_rmrr_units[nr_rmrr].base_pfn = start;
> > +        extra_rmrr_units[nr_rmrr].end_pfn = end;
> > +        extra_rmrr_units[nr_rmrr].dev_count = 0;
> 
> The last assignment isn't really needed.
> 
> > +        if ( *s != '=' )
> > +            continue;
> > +
> > +        do {
> > +            bool_t default_segment = 0;
> > +
> > +            if ( *s == ';' )
> > +                break;
> 
> Can this if() ever be true? *s == '=' on the first iteration, and *s == ','
> on any subsequent one afaics.
Right, thats from the old format parsing code I think.
> 
> > +            stmp = __parse_pci(s + 1, &seg, &bus, &dev, &func, &default_segment);
> > +            if ( !stmp )
> > +                break;
> > +
> > +            /* Not specified segment will be replaced with one from first device. */
> > +            if ( extra_rmrr_units[nr_rmrr].dev_count && default_segment )
> > +                seg = PCI_SEG(extra_rmrr_units[nr_rmrr].sbdf[0]);
> > +
> > +            /* Keep sbdf's even if they differ and later report an error. */
> > +            extra_rmrr_units[nr_rmrr].sbdf[extra_rmrr_units[nr_rmrr].dev_count]                                             = PCI_SBDF(seg, bus, dev, func);
> 
> This line for sure is too long.

Ok, will send with fixes!
Thank you.

Elena
> 
> Jan