Author: kib
Date: Thu Nov 12 00:46:53 2020
New Revision: 367606
URL: https://svnweb.freebsd.org/changeset/base/367606

Log:
  bhyve: avoid allocating BARs above the end of supported physical addresses.
  
  Read CPUID leaf 0x8000008 to determine max supported phys address and
  create BAR region right below it, reserving 1/4 of the supported guest
  physical address space to the 64bit BARs mappings.
  
  PR:    250802 (although the issue from PR is not fixed by the change)
  Noted and reviewed by:        grehan
  Sponsored by: The FreeBSD Foundation
  MFC after:    2 weeks
  Differential revision:        https://reviews.freebsd.org/D27095

Modified:
  head/usr.sbin/bhyve/pci_emul.c

Modified: head/usr.sbin/bhyve/pci_emul.c
==============================================================================
--- head/usr.sbin/bhyve/pci_emul.c      Thu Nov 12 00:29:23 2020        
(r367605)
+++ head/usr.sbin/bhyve/pci_emul.c      Thu Nov 12 00:46:53 2020        
(r367606)
@@ -33,6 +33,9 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/linker_set.h>
+#include <vm/vm.h>
+#include <vm/vm_param.h>
+#include <vm/pmap.h>
 
 #include <ctype.h>
 #include <errno.h>
@@ -46,6 +49,8 @@ __FBSDID("$FreeBSD$");
 
 #include <machine/vmm.h>
 #include <machine/vmm_snapshot.h>
+#include <machine/cpufunc.h>
+#include <machine/specialreg.h>
 #include <vmmapi.h>
 
 #include "acpi.h"
@@ -98,6 +103,7 @@ SET_DECLARE(pci_devemu_set, struct pci_devemu);
 static uint64_t pci_emul_iobase;
 static uint64_t pci_emul_membase32;
 static uint64_t pci_emul_membase64;
+static uint64_t pci_emul_memlim64;
 
 #define        PCI_EMUL_IOBASE         0x2000
 #define        PCI_EMUL_IOLIMIT        0x10000
@@ -108,9 +114,6 @@ SYSRES_MEM(PCI_EMUL_ECFG_BASE, PCI_EMUL_ECFG_SIZE);
 
 #define        PCI_EMUL_MEMLIMIT32     PCI_EMUL_ECFG_BASE
 
-#define        PCI_EMUL_MEMBASE64      0xD000000000UL
-#define        PCI_EMUL_MEMLIMIT64     0xFD00000000UL
-
 static struct pci_devemu *pci_emul_finddev(char *name);
 static void pci_lintr_route(struct pci_devinst *pi);
 static void pci_lintr_update(struct pci_devinst *pi);
@@ -632,7 +635,7 @@ pci_emul_alloc_pbar(struct pci_devinst *pdi, int idx, 
                                baseptr = &hostbase;
                        else
                                baseptr = &pci_emul_membase64;
-                       limit = PCI_EMUL_MEMLIMIT64;
+                       limit = pci_emul_memlim64;
                        mask = PCIM_BAR_MEM_BASE;
                        lobits = PCIM_BAR_MEM_SPACE | PCIM_BAR_MEM_64 |
                                 PCIM_BAR_MEM_PREFETCH;
@@ -1101,12 +1104,25 @@ init_pci(struct vmctx *ctx)
        struct slotinfo *si;
        struct funcinfo *fi;
        size_t lowmem;
-       int bus, slot, func;
-       int error;
+       uint64_t cpu_maxphysaddr, pci_emul_memresv64;
+       u_int regs[4];
+       int bus, slot, func, error;
 
        pci_emul_iobase = PCI_EMUL_IOBASE;
        pci_emul_membase32 = vm_get_lowmem_limit(ctx);
-       pci_emul_membase64 = PCI_EMUL_MEMBASE64;
+
+       do_cpuid(0x80000008, regs);
+       cpu_maxphysaddr = 1ULL << (regs[0] & 0xff);
+       if (cpu_maxphysaddr > VM_MAXUSER_ADDRESS_LA48)
+               cpu_maxphysaddr = VM_MAXUSER_ADDRESS_LA48;
+       pci_emul_memresv64 = cpu_maxphysaddr / 4;
+       /*
+        * Max power of 2 that is less then
+        * cpu_maxphysaddr - pci_emul_memresv64.
+        */
+       pci_emul_membase64 = 1ULL << (flsl(cpu_maxphysaddr -
+           pci_emul_memresv64) - 1);
+       pci_emul_memlim64 = cpu_maxphysaddr;
 
        for (bus = 0; bus < MAXBUSES; bus++) {
                if ((bi = pci_businfo[bus]) == NULL)
_______________________________________________
svn-src-all@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"

Reply via email to