KVM: SVM: Implement workaround for Erratum 383 (67ec6607) · Commits · 戴 / test

arch/x86/include/asm/msr-index.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -110,6 +110,7 @@
		#define MSR_AMD64_PATCH_LOADER 0xc0010020
		#define MSR_AMD64_OSVW_ID_LENGTH 0xc0010140
		#define MSR_AMD64_OSVW_STATUS 0xc0010141
		#define MSR_AMD64_DC_CFG 0xc0011022
		#define MSR_AMD64_IBSFETCHCTL 0xc0011030
		#define MSR_AMD64_IBSFETCHLINAD 0xc0011031
		#define MSR_AMD64_IBSFETCHPHYSAD 0xc0011032

arch/x86/kvm/svm.c

+81 −0

Original line number	Diff line number	Diff line
		@@ -28,6 +28,7 @@
		#include <linux/ftrace_event.h>
		#include <linux/slab.h>

		#include <asm/tlbflush.h>
		#include <asm/desc.h>

		#include <asm/virtext.h>
		@@ -56,6 +57,8 @@ MODULE_LICENSE("GPL");

		#define DEBUGCTL_RESERVED_BITS (~(0x3fULL))

		static bool erratum_383_found __read_mostly;

		static const u32 host_save_user_msrs[] = {
		#ifdef CONFIG_X86_64
		MSR_STAR, MSR_LSTAR, MSR_CSTAR, MSR_SYSCALL_MASK, MSR_KERNEL_GS_BASE,
		@@ -374,6 +377,31 @@ static void svm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
		svm->vmcb->control.event_inj_err = error_code;
		}

		static void svm_init_erratum_383(void)
		{
		u32 low, high;
		int err;
		u64 val;

		/* Only Fam10h is affected */
		if (boot_cpu_data.x86 != 0x10)
		return;

		/* Use _safe variants to not break nested virtualization */
		val = native_read_msr_safe(MSR_AMD64_DC_CFG, &err);
		if (err)
		return;

		val \|= (1ULL << 47);

		low = lower_32_bits(val);
		high = upper_32_bits(val);

		native_write_msr_safe(MSR_AMD64_DC_CFG, low, high);

		erratum_383_found = true;
		}

		static int has_svm(void)
		{
		const char *msg;
		@@ -429,6 +457,8 @@ static int svm_hardware_enable(void *garbage)

		wrmsrl(MSR_VM_HSAVE_PA, page_to_pfn(sd->save_area) << PAGE_SHIFT);

		svm_init_erratum_383();

		return 0;
		}

		@@ -1410,8 +1440,59 @@ static int nm_interception(struct vcpu_svm *svm)
		return 1;
		}

		static bool is_erratum_383(void)
		{
		int err, i;
		u64 value;

		if (!erratum_383_found)
		return false;

		value = native_read_msr_safe(MSR_IA32_MC0_STATUS, &err);
		if (err)
		return false;

		/* Bit 62 may or may not be set for this mce */
		value &= ~(1ULL << 62);

		if (value != 0xb600000000010015ULL)
		return false;

		/* Clear MCi_STATUS registers */
		for (i = 0; i < 6; ++i)
		native_write_msr_safe(MSR_IA32_MCx_STATUS(i), 0, 0);

		value = native_read_msr_safe(MSR_IA32_MCG_STATUS, &err);
		if (!err) {
		u32 low, high;

		value &= ~(1ULL << 2);
		low = lower_32_bits(value);
		high = upper_32_bits(value);

		native_write_msr_safe(MSR_IA32_MCG_STATUS, low, high);
		}

		/* Flush tlb to evict multi-match entries */
		__flush_tlb_all();

		return true;
		}

		static void svm_handle_mce(struct vcpu_svm *svm)
		{
		if (is_erratum_383()) {
		/*
		* Erratum 383 triggered. Guest state is corrupt so kill the
		* guest.
		*/
		pr_err("KVM: Guest triggered AMD Erratum 383\n");

		set_bit(KVM_REQ_TRIPLE_FAULT, &svm->vcpu.requests);

		return;
		}

		/*
		* On an #MC intercept the MCE handler is not called automatically in
		* the host. So do it by hand here.

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