From: Jan Beulich Date: Tue, 19 Oct 2021 08:04:13 +0000 (+0200) Subject: x86/AMD: make HT range dynamic for Fam17 and up X-Git-Tag: archive/raspbian/4.16.0+51-g0941d6cb-1+rpi1~2^2~42^2~64 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=d6e38eea2d806c53d976603717aebf6e5de30a1e;p=xen.git x86/AMD: make HT range dynamic for Fam17 and up At the time of d838ac2539cf ("x86: don't allow Dom0 access to the HT address range") documentation correctly stated that the range was completely fixed. For Fam17 and newer, it lives at the top of physical address space, though. To correctly determine the top of physical address space, we need to account for their physical address reduction, hence the calculation of paddr_bits also gets adjusted. While for paddr_bits < 40 the HT range is completely hidden, there's no need to suppress the range insertion in that case: It'll just have no real meaning. Reported-by: Igor Druzhinin Signed-off-by: Jan Beulich Reviewed-by: Roger Pau Monné --- diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c index 302f7f35d8..4a163afbfc 100644 --- a/xen/arch/x86/cpu/common.c +++ b/xen/arch/x86/cpu/common.c @@ -349,16 +349,23 @@ void __init early_cpu_init(void) eax = cpuid_eax(0x80000000); if ((eax >> 16) == 0x8000 && eax >= 0x80000008) { + ebx = eax >= 0x8000001f ? cpuid_ebx(0x8000001f) : 0; eax = cpuid_eax(0x80000008); + paddr_bits = eax & 0xff; if (paddr_bits > PADDR_BITS) paddr_bits = PADDR_BITS; + vaddr_bits = (eax >> 8) & 0xff; if (vaddr_bits > VADDR_BITS) vaddr_bits = VADDR_BITS; + hap_paddr_bits = ((eax >> 16) & 0xff) ?: paddr_bits; if (hap_paddr_bits > PADDR_BITS) hap_paddr_bits = PADDR_BITS; + + /* Account for SME's physical address space reduction. */ + paddr_bits -= (ebx >> 6) & 0x3f; } if (!(c->x86_vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON))) diff --git a/xen/arch/x86/dom0_build.c b/xen/arch/x86/dom0_build.c index 74b443e509..fe24e11b37 100644 --- a/xen/arch/x86/dom0_build.c +++ b/xen/arch/x86/dom0_build.c @@ -524,8 +524,11 @@ int __init dom0_setup_permissions(struct domain *d) MSI_ADDR_DEST_ID_MASK)); /* HyperTransport range. */ if ( boot_cpu_data.x86_vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON) ) - rc |= iomem_deny_access(d, paddr_to_pfn(0xfdULL << 32), - paddr_to_pfn((1ULL << 40) - 1)); + { + mfn = paddr_to_pfn(1UL << + (boot_cpu_data.x86 < 0x17 ? 40 : paddr_bits)); + rc |= iomem_deny_access(d, mfn - paddr_to_pfn(3UL << 32), mfn - 1); + } /* Remove access to E820_UNUSABLE I/O regions above 1MB. */ for ( i = 0; i < e820.nr_map; i++ )