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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [v3][PATCH 07/16] hvmloader/pci: skip reserved ranges
On 2015/6/17 17:24, Jan Beulich wrote: On 17.06.15 at 11:18, <tiejun.chen@xxxxxxxxx> wrote:On 2015/6/17 17:02, Jan Beulich wrote:On 17.06.15 at 10:26, <tiejun.chen@xxxxxxxxx> wrote:Something hits me to generate another idea, #1. Still allocate all devices as before. #2. Lookup all actual bars to check if they're conflicting RMRR We can skip these bars to keep zero. Then later it would make lookup easily. #3. Need to reallocate these conflicting bars. #3.1 Trying to reallocate them with the remaining resources #3.2 If the remaining resources aren't enough, we need to allocate them from high_mem_resource.That's possible onyl for 64-bit BARs.You're right so this means its not proper to adjust mmio_total to include conflicting reserved ranges and finally moved all conflicting bars to high_mem_resource as Kevin suggested previously, so i high level, we still need to decrease pci_mem_start to populate more RAM to compensate them as I did, right?You probably should do both: Prefer moving things beyond 4Gb, but if not possible increase the MMIO hole. I'm trying to figure out a better solution. Perhaps we can allocate 32-bit bars and 64-bit bars orderly. This may help us bypass those complicated corner cases. #1. We don't calculate how much memory should be compensated to add them to expand something like we though previously. #2. Instead, before allocating bars, we just check if reserved device memory is really conflicting this default region [pci_mem_start, pci_mem_end] #2.1 If not, obviously nothing is changed.#2.2 If yes, we introduce a new local bool, bar32_allocating, which indicates if we want to allocate 32-bit bars and 64-bit bars separately. So here we should set as true, and we also need to set 'bar64_relocate' to relocate bars to 64-bit.
/*
* Check if reserved device memory conflicts current pci memory.
* If yes, we need to first allocate bar32 since reserved devices
* always occupy low memory, and also enable relocating some BARs
* to 64bit as possible.
*/
for ( i = 0; i < memory_map.nr_map ; i++ )
{
reserved_start = memory_map.map[i].addr;
reserved_size = memory_map.map[i].size;
reserved_end = reserved_start + reserved_size;
if ( check_overlap(pci_mem_start, pci_mem_end - pci_mem_start,
reserved_start, reserved_size) )
{
printf("Reserved device memory conflicts current PCI memory,"
" so first to allocate 32-bit BAR and trying to"
" relocating some BARs to 64-bit\n");
bar32_allocating = 1;
if ( !bar64_relocate )
bar64_relocate = 1;
}
}
#2.2 then this also means we may allocate many times so add a label at
the allocation,
+ further_allocate:
/* Assign iomem and ioport resources in descending order of size. */
for ( i = 0; i < nr_bars; i++ )
{
#2.3 Make sure we can allocate all bars separately as we expect,
bar_sz = bars[i].bar_sz;
/*
+ * This means we'd like to first allocate 32bit bar to make sure
+ * all 32bit bars can be allocated as possible.
+ */
+ if ( bars[i].is_64bar && bar32_allocating )
+ continue;
+
+ /*
* Relocate to high memory if the total amount of MMIO needed
* is more than the low MMIO available. Because devices are
* processed in order of bar_sz, this will preferentially
#2.4 We still need to skip reserved device memory
base = (resource->base + bar_sz - 1) & ~(uint64_t)(bar_sz - 1);
bar_data |= (uint32_t)base;
bar_data_upper = (uint32_t)(base >> 32);
+ /*
+ * Skip all reserved device memory.
+ *
+ * Note you need to make sure memory_map.map doesn't go high
memory,
+ * then here we can make life easy.
+ */
+ if ( !using_64bar )
+ {
+ for ( j = 0; j < memory_map.nr_map ; j++ )
+ {
+ if ( memory_map.map[j].type != E820_RAM )
+ {
+ reserved_end = memory_map.map[j].addr +
memory_map.map[j].size;
+ if ( check_overlap(base, bar_sz,
+ memory_map.map[j].addr,
+ memory_map.map[j].size) )
+ {
+ base = reserved_end;
+ continue;
+ }
+ }
+ }
+ }
base += bar_sz;
if ( (base < resource->base) || (base > resource->max) )
#2.5 Then go to the second allocation if necessary
#2.5.1 After we're trying to allocate all 32bit-bars at the first
allocation, we'll check if any 32bit bars are not allocated.
#2.5.1 If all 32bit-bars are allocated, we just set something as follows, + bar32_allocating = 0; + goto further_allocate;then we allocate 64bit-bards at the second allocation. But note this doesn't mean we will allocate 64bit-bars just from highmem since the original mechanism still work at this point, so we're still trying to allocate 64bit-bars from the remaining low pci memory & highmem like before. #2.5.2 If not all 32bit-bars are allocated, we need to populate RAM to extend low pci memory.
#2.5.2.1 Calculate how much memory are still needed
+ /* Calculate the remaining 32bars. */
+ for ( n = 0; n < nr_bars ; n++ )
+ {
+ if ( !bars[n].is_64bar )
+ {
+ uint32_t devfn32, bar_reg32, bar_data32;
+ uint64_t bar_sz32;
+ devfn32 = bars[n].devfn;
+ bar_reg32 = bars[n].bar_reg;
+ bar_sz32 = bars[n].bar_sz;
+ bar_data32 = pci_readl(devfn32, bar_reg32);
+ if ( !bar_data32 )
+ mmio32_unallocated_total += bar_sz32;
+ }
+ }
#2.5.2.2 populate these memory
+ cur_pci_mem_start = pci_mem_start -
mmio32_unallocated_total;
+ relocate_ram_for_pci_memory(cur_pci_mem_start); + exp_mem_resource.base = cur_pci_mem_start; + exp_mem_resource.max = pci_mem_start;#2.5.2.3 goto further_allocate to reallocate the remaining 32bit-bars. Note we should make sure we allocate them just from exp_mem_resource above. #2.5.3 In theory we can allocate all 32bit-bars successfully. But we can check if mmio32_unallocated_total is already set to make sure we don't fall into an infinite loop. #2.5.4 Then as before, we would go to allocate 64bit-bars at the first allocation.
The following patch is trying to implement my idea,
diff --git a/tools/firmware/hvmloader/pci.c b/tools/firmware/hvmloader/pci.c
index 5ff87a7..f2953c0 100644
--- a/tools/firmware/hvmloader/pci.c
+++ b/tools/firmware/hvmloader/pci.c
@@ -38,6 +38,31 @@ uint64_t pci_hi_mem_start = 0, pci_hi_mem_end = 0;
enum virtual_vga virtual_vga = VGA_none;
unsigned long igd_opregion_pgbase = 0;
+static void relocate_ram_for_pci_memory(unsigned long cur_pci_mem_start)
+{
+ struct xen_add_to_physmap xatp;
+ unsigned int nr_pages = min_t(
+ unsigned int,
+ hvm_info->low_mem_pgend - (cur_pci_mem_start >> PAGE_SHIFT),
+ (1u << 16) - 1);
+ if ( hvm_info->high_mem_pgend == 0 )
+ hvm_info->high_mem_pgend = 1ull << (32 - PAGE_SHIFT);
+ hvm_info->low_mem_pgend -= nr_pages;
+ printf("Relocating 0x%x pages from "PRIllx" to "PRIllx\
+ " for lowmem MMIO hole\n",
+ nr_pages,
+ PRIllx_arg(((uint64_t)hvm_info->low_mem_pgend)<<PAGE_SHIFT),
+ PRIllx_arg(((uint64_t)hvm_info->high_mem_pgend)<<PAGE_SHIFT));
+ xatp.domid = DOMID_SELF;
+ xatp.space = XENMAPSPACE_gmfn_range;
+ xatp.idx = hvm_info->low_mem_pgend;
+ xatp.gpfn = hvm_info->high_mem_pgend;
+ xatp.size = nr_pages;
+ if ( hypercall_memory_op(XENMEM_add_to_physmap, &xatp) != 0 )
+ BUG();
+ hvm_info->high_mem_pgend += nr_pages;
+}
+
void pci_setup(void)
{
uint8_t is_64bar, using_64bar, bar64_relocate = 0;
@@ -50,7 +75,7 @@ void pci_setup(void)
/* Resources assignable to PCI devices via BARs. */
struct resource {
uint64_t base, max;
- } *resource, mem_resource, high_mem_resource, io_resource;
+ } *resource, mem_resource, high_mem_resource, io_resource,
exp_mem_resource;
/* Create a list of device BARs in descending order of size. */
struct bars {
@@ -59,8 +84,11 @@ void pci_setup(void)
uint32_t bar_reg;
uint64_t bar_sz;
} *bars = (struct bars *)scratch_start;
- unsigned int i, nr_bars = 0;
- uint64_t mmio_hole_size = 0;
+ unsigned int i, j, n, nr_bars = 0;
+ uint64_t mmio_hole_size = 0, reserved_start, reserved_end,
reserved_size;
+ bool bar32_allocating = 0;
+ uint64_t mmio32_unallocated_total = 0;
+ unsigned long cur_pci_mem_start = 0;
const char *s;
/*
@@ -309,29 +337,31 @@ void pci_setup(void)
}
/* Relocate RAM that overlaps PCI space (in 64k-page chunks). */
+ cur_pci_mem_start = pci_mem_start;
while ( (pci_mem_start >> PAGE_SHIFT) < hvm_info->low_mem_pgend )
+ relocate_ram_for_pci_memory(cur_pci_mem_start);
+
+ /*
+ * Check if reserved device memory conflicts current pci memory.
+ * If yes, we need to first allocate bar32 since reserved devices
+ * always occupy low memory, and also enable relocating some BARs
+ * to 64bit as possible.
+ */
+ for ( i = 0; i < memory_map.nr_map ; i++ )
{
- struct xen_add_to_physmap xatp;
- unsigned int nr_pages = min_t(
- unsigned int,
- hvm_info->low_mem_pgend - (pci_mem_start >> PAGE_SHIFT),
- (1u << 16) - 1);
- if ( hvm_info->high_mem_pgend == 0 )
- hvm_info->high_mem_pgend = 1ull << (32 - PAGE_SHIFT);
- hvm_info->low_mem_pgend -= nr_pages;
- printf("Relocating 0x%x pages from "PRIllx" to "PRIllx\
- " for lowmem MMIO hole\n",
- nr_pages,
- PRIllx_arg(((uint64_t)hvm_info->low_mem_pgend)<<PAGE_SHIFT),
-
PRIllx_arg(((uint64_t)hvm_info->high_mem_pgend)<<PAGE_SHIFT));
- xatp.domid = DOMID_SELF;
- xatp.space = XENMAPSPACE_gmfn_range;
- xatp.idx = hvm_info->low_mem_pgend;
- xatp.gpfn = hvm_info->high_mem_pgend;
- xatp.size = nr_pages;
- if ( hypercall_memory_op(XENMEM_add_to_physmap, &xatp) != 0 )
- BUG();
- hvm_info->high_mem_pgend += nr_pages;
+ reserved_start = memory_map.map[i].addr;
+ reserved_size = memory_map.map[i].size;
+ reserved_end = reserved_start + reserved_size;
+ if ( check_overlap(pci_mem_start, pci_mem_end - pci_mem_start,
+ reserved_start, reserved_size) )
+ {
+ printf("Reserved device memory conflicts current PCI memory,"
+ " so first to allocate 32-bit BAR and trying to"
+ " relocating some BARs to 64-bit\n");
+ bar32_allocating = 1;
+ if ( !bar64_relocate )
+ bar64_relocate = 1;
+ }
}
high_mem_resource.base = ((uint64_t)hvm_info->high_mem_pgend) <<
PAGE_SHIFT;
@@ -352,6 +382,7 @@ void pci_setup(void)
io_resource.base = 0xc000;
io_resource.max = 0x10000;
+ further_allocate:
/* Assign iomem and ioport resources in descending order of size. */
for ( i = 0; i < nr_bars; i++ )
{
@@ -360,6 +391,13 @@ void pci_setup(void)
bar_sz = bars[i].bar_sz;
/*
+ * This means we'd like to first allocate 32bit bar to make sure
+ * all 32bit bars can be allocated as possible.
+ */
+ if ( bars[i].is_64bar && bar32_allocating )
+ continue;
+
+ /*
* Relocate to high memory if the total amount of MMIO needed
* is more than the low MMIO available. Because devices are
* processed in order of bar_sz, this will preferentially
@@ -395,7 +433,14 @@ void pci_setup(void)
bar_data &= ~PCI_BASE_ADDRESS_MEM_MASK;
}
else {
- resource = &mem_resource;
+ /*
+ * This menas we're trying to use that expanded
+ * memory to reallocate 32bars.
+ */
+ if ( mmio32_unallocated_total )
+ resource = &exp_mem_resource;
+ else
+ resource = &mem_resource;
bar_data &= ~PCI_BASE_ADDRESS_MEM_MASK;
}
mmio_total -= bar_sz;
@@ -409,6 +454,29 @@ void pci_setup(void)
base = (resource->base + bar_sz - 1) & ~(uint64_t)(bar_sz - 1);
bar_data |= (uint32_t)base;
bar_data_upper = (uint32_t)(base >> 32);
+ /*
+ * Skip all reserved device memory.
+ *
+ * Note you need to make sure memory_map.map doesn't go high
memory,
+ * then here we can make life easy.
+ */
+ if ( !using_64bar )
+ {
+ for ( j = 0; j < memory_map.nr_map ; j++ )
+ {
+ if ( memory_map.map[j].type != E820_RAM )
+ {
+ reserved_end = memory_map.map[j].addr +
memory_map.map[j].size;
+ if ( check_overlap(base, bar_sz,
+ memory_map.map[j].addr,
+ memory_map.map[j].size) )
+ {
+ base = reserved_end;
+ continue;
+ }
+ }
+ }
+ }
base += bar_sz;
if ( (base < resource->base) || (base > resource->max) )
@@ -439,6 +507,54 @@ void pci_setup(void)
else
cmd |= PCI_COMMAND_IO;
pci_writew(devfn, PCI_COMMAND, cmd);
+
+ /* If we finish allocating bar32 at the first time. */
+ if ( i == nr_bars && bar32_allocating )
+ {
+ /*
+ * We won't repeat to populate more RAM to finalize
+ * allocate all 32bars, so just go to allocate 64bit-bars.
+ */
+ if ( mmio32_unallocated_total )
+ {
+ bar32_allocating = 0;
+ mmio32_unallocated_total = 0;
+ high_mem_resource.base =
+ ((uint64_t)hvm_info->high_mem_pgend) << PAGE_SHIFT;
+ goto further_allocate;
+ }
+
+ /* Calculate the remaining 32bars. */
+ for ( n = 0; n < nr_bars ; n++ )
+ {
+ if ( !bars[n].is_64bar )
+ {
+ uint32_t devfn32, bar_reg32, bar_data32;
+ uint64_t bar_sz32;
+ devfn32 = bars[n].devfn;
+ bar_reg32 = bars[n].bar_reg;
+ bar_sz32 = bars[n].bar_sz;
+ bar_data32 = pci_readl(devfn32, bar_reg32);
+ if ( !bar_data32 )
+ mmio32_unallocated_total += bar_sz32;
+ }
+ }
+
+ /*
+ * We have to populate more RAM to further allocate
+ * the remaining 32bars.
+ */
+ if ( mmio32_unallocated_total )
+ {
+ cur_pci_mem_start = pci_mem_start -
mmio32_unallocated_total;
+ relocate_ram_for_pci_memory(cur_pci_mem_start);
+ exp_mem_resource.base = cur_pci_mem_start;
+ exp_mem_resource.max = pci_mem_start;
+ }
+ else
+ bar32_allocating = 0;
+ goto further_allocate;
+ }
}
if ( pci_hi_mem_start )
Thanks
Tiejun
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