diff options
Diffstat (limited to 'arch/x86/xen/enlighten_pv.c')
| -rw-r--r-- | arch/x86/xen/enlighten_pv.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index 093b78c8bbec..93b658248d01 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -68,6 +68,7 @@ #include <asm/reboot.h> #include <asm/hypervisor.h> #include <asm/mach_traps.h> +#include <asm/mtrr.h> #include <asm/mwait.h> #include <asm/pci_x86.h> #include <asm/cpu.h> @@ -119,6 +120,54 @@ static int __init parse_xen_msr_safe(char *str) } early_param("xen_msr_safe", parse_xen_msr_safe); +/* Get MTRR settings from Xen and put them into mtrr_state. */ +static void __init xen_set_mtrr_data(void) +{ +#ifdef CONFIG_MTRR + struct xen_platform_op op = { + .cmd = XENPF_read_memtype, + .interface_version = XENPF_INTERFACE_VERSION, + }; + unsigned int reg; + unsigned long mask; + uint32_t eax, width; + static struct mtrr_var_range var[MTRR_MAX_VAR_RANGES] __initdata; + + /* Get physical address width (only 64-bit cpus supported). */ + width = 36; + eax = cpuid_eax(0x80000000); + if ((eax >> 16) == 0x8000 && eax >= 0x80000008) { + eax = cpuid_eax(0x80000008); + width = eax & 0xff; + } + + for (reg = 0; reg < MTRR_MAX_VAR_RANGES; reg++) { + op.u.read_memtype.reg = reg; + if (HYPERVISOR_platform_op(&op)) + break; + + /* + * Only called in dom0, which has all RAM PFNs mapped at + * RAM MFNs, and all PCI space etc. is identity mapped. + * This means we can treat MFN == PFN regarding MTRR settings. + */ + var[reg].base_lo = op.u.read_memtype.type; + var[reg].base_lo |= op.u.read_memtype.mfn << PAGE_SHIFT; + var[reg].base_hi = op.u.read_memtype.mfn >> (32 - PAGE_SHIFT); + mask = ~((op.u.read_memtype.nr_mfns << PAGE_SHIFT) - 1); + mask &= (1UL << width) - 1; + if (mask) + mask |= MTRR_PHYSMASK_V; + var[reg].mask_lo = mask; + var[reg].mask_hi = mask >> 32; + } + + /* Only overwrite MTRR state if any MTRR could be got from Xen. */ + if (reg) + mtrr_overwrite_state(var, reg, MTRR_TYPE_UNCACHABLE); +#endif +} + static void __init xen_pv_init_platform(void) { /* PV guests can't operate virtio devices without grants. */ @@ -135,6 +184,11 @@ static void __init xen_pv_init_platform(void) /* pvclock is in shared info area */ xen_init_time_ops(); + + if (xen_initial_domain()) + xen_set_mtrr_data(); + else + mtrr_overwrite_state(NULL, 0, MTRR_TYPE_WRBACK); } static void __init xen_pv_guest_late_init(void) |