Date: Thu, 4 Jun 2015 02:12:24 +0000 (UTC) From: Neel Natu <neel@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r283973 - head/sys/amd64/vmm/amd Message-ID: <201506040212.t542CO4N036509@svn.freebsd.org>
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Author: neel Date: Thu Jun 4 02:12:23 2015 New Revision: 283973 URL: https://svnweb.freebsd.org/changeset/base/283973 Log: Use tunable 'hw.vmm.svm.features' to disable specific SVM features even though they might be available in hardware. Use tunable 'hw.vmm.svm.num_asids' to limit the number of ASIDs used by the hypervisor. MFC after: 1 week Modified: head/sys/amd64/vmm/amd/svm.c Modified: head/sys/amd64/vmm/amd/svm.c ============================================================================== --- head/sys/amd64/vmm/amd/svm.c Thu Jun 4 01:52:17 2015 (r283972) +++ head/sys/amd64/vmm/amd/svm.c Thu Jun 4 02:12:23 2015 (r283973) @@ -102,8 +102,8 @@ static MALLOC_DEFINE(M_SVM_VLAPIC, "svm- /* Per-CPU context area. */ extern struct pcpu __pcpu[]; -static uint32_t svm_feature; /* AMD SVM features. */ -SYSCTL_UINT(_hw_vmm_svm, OID_AUTO, features, CTLFLAG_RD, &svm_feature, 0, +static uint32_t svm_feature = ~0U; /* AMD SVM features. */ +SYSCTL_UINT(_hw_vmm_svm, OID_AUTO, features, CTLFLAG_RDTUN, &svm_feature, 0, "SVM features advertised by CPUID.8000000AH:EDX"); static int disable_npf_assist; @@ -112,7 +112,7 @@ SYSCTL_INT(_hw_vmm_svm, OID_AUTO, disabl /* Maximum ASIDs supported by the processor */ static uint32_t nasid; -SYSCTL_UINT(_hw_vmm_svm, OID_AUTO, num_asids, CTLFLAG_RD, &nasid, 0, +SYSCTL_UINT(_hw_vmm_svm, OID_AUTO, num_asids, CTLFLAG_RDTUN, &nasid, 0, "Number of ASIDs supported by this processor"); /* Current ASID generation for each host cpu */ @@ -174,9 +174,14 @@ check_svm_features(void) /* CPUID Fn8000_000A is for SVM */ do_cpuid(0x8000000A, regs); - svm_feature = regs[3]; + svm_feature &= regs[3]; - nasid = regs[1]; + /* + * The number of ASIDs can be configured to be less than what is + * supported by the hardware but not more. + */ + if (nasid == 0 || nasid > regs[1]) + nasid = regs[1]; KASSERT(nasid > 1, ("Insufficient ASIDs for guests: %#x", nasid)); /* bhyve requires the Nested Paging feature */
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