From 6bf08a8dcd1ef13e542f08fc3b1ce6cf64ae63b6 Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Tue, 29 Jan 2013 16:32:16 -0500 Subject: x86, AMD: Clean up init_amd() Clean up multiple declarations of variable used for rd/wrmsr. Signed-off-by: Boris Ostrovsky Link: http://lkml.kernel.org/r/1359495136-23244-1-git-send-email-ostr@amd64.org Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/amd.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) (limited to 'arch/x86/kernel/cpu/amd.c') diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 15239fffd6fe..dd4a5b685a00 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -518,10 +518,9 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c) static void __cpuinit init_amd(struct cpuinfo_x86 *c) { u32 dummy; - -#ifdef CONFIG_SMP unsigned long long value; +#ifdef CONFIG_SMP /* * Disable TLB flush filter by setting HWCR.FFDIS on K8 * bit 6 of msr C001_0015 @@ -559,12 +558,10 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) * (AMD Erratum #110, docId: 25759). */ if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) { - u64 val; - clear_cpu_cap(c, X86_FEATURE_LAHF_LM); - if (!rdmsrl_amd_safe(0xc001100d, &val)) { - val &= ~(1ULL << 32); - wrmsrl_amd_safe(0xc001100d, val); + if (!rdmsrl_amd_safe(0xc001100d, &value)) { + value &= ~(1ULL << 32); + wrmsrl_amd_safe(0xc001100d, value); } } @@ -617,13 +614,12 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) if ((c->x86 == 0x15) && (c->x86_model >= 0x10) && (c->x86_model <= 0x1f) && !cpu_has(c, X86_FEATURE_TOPOEXT)) { - u64 val; - if (!rdmsrl_safe(0xc0011005, &val)) { - val |= 1ULL << 54; - wrmsrl_safe(0xc0011005, val); - rdmsrl(0xc0011005, val); - if (val & (1ULL << 54)) { + if (!rdmsrl_safe(0xc0011005, &value)) { + value |= 1ULL << 54; + wrmsrl_safe(0xc0011005, value); + rdmsrl(0xc0011005, value); + if (value & (1ULL << 54)) { set_cpu_cap(c, X86_FEATURE_TOPOEXT); printk(KERN_INFO FW_INFO "CPU: Re-enabling " "disabled Topology Extensions Support\n"); @@ -637,11 +633,10 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) */ if ((c->x86 == 0x15) && (c->x86_model >= 0x02) && (c->x86_model < 0x20)) { - u64 val; - if (!rdmsrl_safe(0xc0011021, &val) && !(val & 0x1E)) { - val |= 0x1E; - wrmsrl_safe(0xc0011021, val); + if (!rdmsrl_safe(0xc0011021, &value) && !(value & 0x1E)) { + value |= 0x1E; + wrmsrl_safe(0xc0011021, value); } } -- cgit v1.2.1 From f0322bd341fd63261527bf84afd3272bcc2e8dd3 Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Tue, 29 Jan 2013 16:32:49 -0500 Subject: x86, AMD: Enable WC+ memory type on family 10 processors In some cases BIOS may not enable WC+ memory type on family 10 processors, instead converting what would be WC+ memory to CD type. On guests using nested pages this could result in performance degradation. This patch enables WC+. Signed-off-by: Boris Ostrovsky Link: http://lkml.kernel.org/r/1359495169-23278-1-git-send-email-ostr@amd64.org Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/amd.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) (limited to 'arch/x86/kernel/cpu/amd.c') diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index dd4a5b685a00..721ef3208eb5 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -698,13 +698,11 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) if (c->x86 > 0x11) set_cpu_cap(c, X86_FEATURE_ARAT); - /* - * Disable GART TLB Walk Errors on Fam10h. We do this here - * because this is always needed when GART is enabled, even in a - * kernel which has no MCE support built in. - */ if (c->x86 == 0x10) { /* + * Disable GART TLB Walk Errors on Fam10h. We do this here + * because this is always needed when GART is enabled, even in a + * kernel which has no MCE support built in. * BIOS should disable GartTlbWlk Errors themself. If * it doesn't do it here as suggested by the BKDG. * @@ -718,6 +716,19 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) mask |= (1 << 10); wrmsrl_safe(MSR_AMD64_MCx_MASK(4), mask); } + + /* + * On family 10h BIOS may not have properly enabled WC+ support, + * causing it to be converted to CD memtype. This may result in + * performance degradation for certain nested-paging guests. + * Prevent this conversion by clearing bit 24 in + * MSR_AMD64_BU_CFG2. + */ + if (c->x86 == 0x10) { + rdmsrl(MSR_AMD64_BU_CFG2, value); + value &= ~(1ULL << 24); + wrmsrl(MSR_AMD64_BU_CFG2, value); + } } rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy); -- cgit v1.2.1 From 52d3d06e706bdde3d6c5c386deb065c3b4c51618 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Tue, 19 Feb 2013 19:33:12 +0100 Subject: x86, cpu, amd: Fix WC+ workaround for older virtual hosts The WC+ workaround for F10h introduces a new MSR and kvm host #GPs on accesses to unknown MSRs if paravirt is not compiled in. Use the exception-handling MSR accessors so as not to break 3.8 and later guests booting on older hosts. Remove a redundant family check while at it. Cc: Gleb Natapov Cc: Boris Ostrovsky Signed-off-by: Borislav Petkov Link: http://lkml.kernel.org/r/1361298793-31834-1-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/amd.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'arch/x86/kernel/cpu/amd.c') diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 721ef3208eb5..163af4a91d09 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -723,12 +723,14 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c) * performance degradation for certain nested-paging guests. * Prevent this conversion by clearing bit 24 in * MSR_AMD64_BU_CFG2. + * + * NOTE: we want to use the _safe accessors so as not to #GP kvm + * guests on older kvm hosts. */ - if (c->x86 == 0x10) { - rdmsrl(MSR_AMD64_BU_CFG2, value); - value &= ~(1ULL << 24); - wrmsrl(MSR_AMD64_BU_CFG2, value); - } + + rdmsrl_safe(MSR_AMD64_BU_CFG2, &value); + value &= ~(1ULL << 24); + wrmsrl_safe(MSR_AMD64_BU_CFG2, value); } rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy); -- cgit v1.2.1