From: Wei Huang <wei.huang2@amd.com>
To: "'xen-devel@lists.xensource.com'" <xen-devel@lists.xensource.com>,
keir@xen.org, Jan Beulich <JBeulich@novell.com>
Subject: [PATCH] FPU LWP 8/8: LWP: Add LWP support for SVM guests
Date: Tue, 3 May 2011 15:18:45 -0500 [thread overview]
Message-ID: <4DC06325.5040906@amd.com> (raw)
[-- Attachment #1: Type: text/plain, Size: 334 bytes --]
LWP: Add LWP support for SVM guests
This patch enables SVM to handle LWP related MSRs and CPUID. It
intercepts guests read/write to LWP_CFG. It also save/restore LWP_CFG
when guests touch this MSR. The LWP_CBADDR MSR is not intercepted
because this MSR is handled by xsave/xrstor.
Signed-off-by: Wei Huang <wei.huang2@amd.com>
[-- Attachment #2: lwp8.txt --]
[-- Type: text/plain, Size: 6095 bytes --]
# HG changeset patch
# User Wei Huang <wei.huang2@amd.com>
# Date 1304449528 18000
# Node ID 8b4b5cad0089f9c215e84dbcf0145ea533d3ee40
# Parent dbd907bf172c399fc432b973a6668f1ba8545292
LWP: Add LWP support for SVM guests
This patch enables SVM to handle LWP related MSRs and CPUID. It intercepts guests read/write to LWP_CFG. It also save/restore LWP_CFG when guests touch this MSR. The LWP_CBADDR MSR is not intercepted because this MSR is handled by xsave/xrstor.
Signed-off-by: Wei Huang <wei.huang2@amd.com>
diff -r dbd907bf172c -r 8b4b5cad0089 xen/arch/x86/hvm/svm/svm.c
--- a/xen/arch/x86/hvm/svm/svm.c Tue May 03 14:01:30 2011 -0500
+++ b/xen/arch/x86/hvm/svm/svm.c Tue May 03 14:05:28 2011 -0500
@@ -58,7 +58,8 @@
#include <asm/hvm/trace.h>
#include <asm/hap.h>
#include <asm/apic.h>
-#include <asm/debugger.h>
+#include <asm/debugger.h>
+#include <asm/xstate.h>
u32 svm_feature_flags;
@@ -695,6 +696,44 @@
*(u16 *)(hypercall_page + (__HYPERVISOR_iret * 32)) = 0x0b0f; /* ud2 */
}
+static inline void svm_lwp_save(struct vcpu *v)
+{
+ /* Don't mess up with other guests. Disable LWP for next VCPU. */
+ if ( v->arch.hvm_svm.guest_lwp_cfg )
+ wrmsrl(MSR_AMD64_LWP_CFG, 0x0);
+}
+
+static inline void svm_lwp_load(struct vcpu *v)
+{
+ /* Only LWP_CFG is reloaded. LWP_CBADDR will be reloaded via xrstor. */
+ if ( v->arch.hvm_svm.guest_lwp_cfg )
+ wrmsrl(MSR_AMD64_LWP_CFG, v->arch.hvm_svm.guest_lwp_cfg);
+}
+
+/* Update LWP_CFG MSR (0xc0000105). Return -1 if error; otherwise returns 0. */
+static int svm_update_lwp_cfg(struct vcpu *v, uint64_t msr_content)
+{
+ unsigned int eax, ebx, ecx, edx;
+ uint32_t msr_low;
+
+ if ( cpu_has_lwp )
+ {
+ hvm_cpuid(0x8000001c, &eax, &ebx, &ecx, &edx);
+ msr_low = (uint32_t)msr_content;
+
+ /* generate #GP if guest tries to turn on unsupported features. */
+ if ( msr_low & ~edx)
+ return -1;
+
+ wrmsrl(MSR_AMD64_LWP_CFG, msr_content);
+ /* CPU might automatically correct reserved bits. So read it back. */
+ rdmsrl(MSR_AMD64_LWP_CFG, msr_content);
+ v->arch.hvm_svm.guest_lwp_cfg = msr_content;
+ }
+
+ return 0;
+}
+
static void svm_ctxt_switch_from(struct vcpu *v)
{
int cpu = smp_processor_id();
@@ -703,6 +742,7 @@
svm_save_dr(v);
vpmu_save(v);
+ svm_lwp_save(v);
svm_sync_vmcb(v);
svm_vmload(per_cpu(root_vmcb, cpu));
@@ -746,6 +786,7 @@
svm_vmload(vmcb);
vmcb->cleanbits.bytes = 0;
vpmu_load(v);
+ svm_lwp_load(v);
if ( cpu_has_rdtscp )
wrmsrl(MSR_TSC_AUX, hvm_msr_tsc_aux(v));
@@ -1120,6 +1161,24 @@
if ( vlapic_hw_disabled(vcpu_vlapic(v)) )
__clear_bit(X86_FEATURE_APIC & 31, edx);
break;
+ case 0x8000001c:
+ {
+ /* LWP capability CPUID */
+ uint64_t lwp_cfg = v->arch.hvm_svm.guest_lwp_cfg;
+
+ if ( cpu_has_lwp )
+ {
+ if ( !(v->arch.xcr0 & XSTATE_LWP) )
+ {
+ *eax = 0x0;
+ break;
+ }
+
+ /* turn on available bit and other features specified in lwp_cfg */
+ *eax = (*edx & lwp_cfg) | 0x00000001;
+ }
+ break;
+ }
default:
break;
}
@@ -1227,6 +1286,10 @@
*msr_content = vmcb_get_lastinttoip(vmcb);
break;
+ case MSR_AMD64_LWP_CFG:
+ *msr_content = v->arch.hvm_svm.guest_lwp_cfg;
+ break;
+
case MSR_K7_PERFCTR0:
case MSR_K7_PERFCTR1:
case MSR_K7_PERFCTR2:
@@ -1323,6 +1386,11 @@
case MSR_IA32_LASTINTTOIP:
vmcb_set_lastinttoip(vmcb, msr_content);
+ break;
+
+ case MSR_AMD64_LWP_CFG:
+ if ( svm_update_lwp_cfg(v, msr_content) < 0 )
+ goto gpf;
break;
case MSR_K7_PERFCTR0:
diff -r dbd907bf172c -r 8b4b5cad0089 xen/arch/x86/hvm/svm/vmcb.c
--- a/xen/arch/x86/hvm/svm/vmcb.c Tue May 03 14:01:30 2011 -0500
+++ b/xen/arch/x86/hvm/svm/vmcb.c Tue May 03 14:05:28 2011 -0500
@@ -120,6 +120,11 @@
svm_disable_intercept_for_msr(v, MSR_LSTAR);
svm_disable_intercept_for_msr(v, MSR_STAR);
svm_disable_intercept_for_msr(v, MSR_SYSCALL_MASK);
+
+ /* LWP_CBADDR MSR is saved and restored by FPU code. So SVM doesn't need to
+ * intercept it. */
+ if ( cpu_has_lwp )
+ svm_disable_intercept_for_msr(v, MSR_AMD64_LWP_CBADDR);
vmcb->_msrpm_base_pa = (u64)virt_to_maddr(arch_svm->msrpm);
vmcb->_iopm_base_pa = (u64)virt_to_maddr(hvm_io_bitmap);
diff -r dbd907bf172c -r 8b4b5cad0089 xen/include/asm-x86/cpufeature.h
--- a/xen/include/asm-x86/cpufeature.h Tue May 03 14:01:30 2011 -0500
+++ b/xen/include/asm-x86/cpufeature.h Tue May 03 14:05:28 2011 -0500
@@ -208,6 +208,8 @@
#define cpu_has_xsave boot_cpu_has(X86_FEATURE_XSAVE)
+#define cpu_has_lwp boot_cpu_has(X86_FEATURE_LWP)
+
#define cpu_has_arch_perfmon boot_cpu_has(X86_FEATURE_ARCH_PERFMON)
#define cpu_has_rdtscp boot_cpu_has(X86_FEATURE_RDTSCP)
diff -r dbd907bf172c -r 8b4b5cad0089 xen/include/asm-x86/hvm/svm/vmcb.h
--- a/xen/include/asm-x86/hvm/svm/vmcb.h Tue May 03 14:01:30 2011 -0500
+++ b/xen/include/asm-x86/hvm/svm/vmcb.h Tue May 03 14:05:28 2011 -0500
@@ -512,6 +512,9 @@
uint64_t guest_sysenter_cs;
uint64_t guest_sysenter_esp;
uint64_t guest_sysenter_eip;
+
+ /* AMD lightweight profiling MSR */
+ uint64_t guest_lwp_cfg;
};
struct vmcb_struct *alloc_vmcb(void);
diff -r dbd907bf172c -r 8b4b5cad0089 xen/include/asm-x86/msr-index.h
--- a/xen/include/asm-x86/msr-index.h Tue May 03 14:01:30 2011 -0500
+++ b/xen/include/asm-x86/msr-index.h Tue May 03 14:05:28 2011 -0500
@@ -253,6 +253,10 @@
#define MSR_AMD_PATCHLEVEL 0x0000008b
#define MSR_AMD_PATCHLOADER 0xc0010020
+/* AMD Lightweight Profiling MSRs */
+#define MSR_AMD64_LWP_CFG 0xc0000105
+#define MSR_AMD64_LWP_CBADDR 0xc0000106
+
/* AMD OS Visible Workaround MSRs */
#define MSR_AMD_OSVW_ID_LENGTH 0xc0010140
#define MSR_AMD_OSVW_STATUS 0xc0010141
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