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authorLinus Torvalds <torvalds@linux-foundation.org>2020-04-08 10:56:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-08 10:56:50 -0700
commit0339eb95403fb4664219be344a9399a3fdf1fae1 (patch)
tree76a6cb0d0cfcf8712867bf7c34cef078245f790b /arch/x86/kvm/svm/vmenter.S
parent9bb715260ed4cef6948cb2e05cf670462367da71 (diff)
parentdbef2808af6c594922fe32833b30f55f35e9da6d (diff)
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull more kvm updates from Paolo Bonzini: "s390: - nested virtualization fixes x86: - split svm.c - miscellaneous fixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: VMX: fix crash cleanup when KVM wasn't used KVM: X86: Filter out the broadcast dest for IPI fastpath KVM: s390: vsie: Fix possible race when shadowing region 3 tables KVM: s390: vsie: Fix delivery of addressing exceptions KVM: s390: vsie: Fix region 1 ASCE sanity shadow address checks KVM: nVMX: don't clear mtf_pending when nested events are blocked KVM: VMX: Remove unnecessary exception trampoline in vmx_vmenter KVM: SVM: Split svm_vcpu_run inline assembly to separate file KVM: SVM: Move SEV code to separate file KVM: SVM: Move AVIC code to separate file KVM: SVM: Move Nested SVM Implementation to nested.c kVM SVM: Move SVM related files to own sub-directory
Diffstat (limited to 'arch/x86/kvm/svm/vmenter.S')
-rw-r--r--arch/x86/kvm/svm/vmenter.S162
1 files changed, 162 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
new file mode 100644
index 000000000000..fa1af90067e9
--- /dev/null
+++ b/arch/x86/kvm/svm/vmenter.S
@@ -0,0 +1,162 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/linkage.h>
+#include <asm/asm.h>
+#include <asm/bitsperlong.h>
+#include <asm/kvm_vcpu_regs.h>
+
+#define WORD_SIZE (BITS_PER_LONG / 8)
+
+/* Intentionally omit RAX as it's context switched by hardware */
+#define VCPU_RCX __VCPU_REGS_RCX * WORD_SIZE
+#define VCPU_RDX __VCPU_REGS_RDX * WORD_SIZE
+#define VCPU_RBX __VCPU_REGS_RBX * WORD_SIZE
+/* Intentionally omit RSP as it's context switched by hardware */
+#define VCPU_RBP __VCPU_REGS_RBP * WORD_SIZE
+#define VCPU_RSI __VCPU_REGS_RSI * WORD_SIZE
+#define VCPU_RDI __VCPU_REGS_RDI * WORD_SIZE
+
+#ifdef CONFIG_X86_64
+#define VCPU_R8 __VCPU_REGS_R8 * WORD_SIZE
+#define VCPU_R9 __VCPU_REGS_R9 * WORD_SIZE
+#define VCPU_R10 __VCPU_REGS_R10 * WORD_SIZE
+#define VCPU_R11 __VCPU_REGS_R11 * WORD_SIZE
+#define VCPU_R12 __VCPU_REGS_R12 * WORD_SIZE
+#define VCPU_R13 __VCPU_REGS_R13 * WORD_SIZE
+#define VCPU_R14 __VCPU_REGS_R14 * WORD_SIZE
+#define VCPU_R15 __VCPU_REGS_R15 * WORD_SIZE
+#endif
+
+ .text
+
+/**
+ * __svm_vcpu_run - Run a vCPU via a transition to SVM guest mode
+ * @vmcb_pa: unsigned long
+ * @regs: unsigned long * (to guest registers)
+ */
+SYM_FUNC_START(__svm_vcpu_run)
+ push %_ASM_BP
+ mov %_ASM_SP, %_ASM_BP
+#ifdef CONFIG_X86_64
+ push %r15
+ push %r14
+ push %r13
+ push %r12
+#else
+ push %edi
+ push %esi
+#endif
+ push %_ASM_BX
+
+ /* Save @regs. */
+ push %_ASM_ARG2
+
+ /* Save @vmcb. */
+ push %_ASM_ARG1
+
+ /* Move @regs to RAX. */
+ mov %_ASM_ARG2, %_ASM_AX
+
+ /* Load guest registers. */
+ mov VCPU_RCX(%_ASM_AX), %_ASM_CX
+ mov VCPU_RDX(%_ASM_AX), %_ASM_DX
+ mov VCPU_RBX(%_ASM_AX), %_ASM_BX
+ mov VCPU_RBP(%_ASM_AX), %_ASM_BP
+ mov VCPU_RSI(%_ASM_AX), %_ASM_SI
+ mov VCPU_RDI(%_ASM_AX), %_ASM_DI
+#ifdef CONFIG_X86_64
+ mov VCPU_R8 (%_ASM_AX), %r8
+ mov VCPU_R9 (%_ASM_AX), %r9
+ mov VCPU_R10(%_ASM_AX), %r10
+ mov VCPU_R11(%_ASM_AX), %r11
+ mov VCPU_R12(%_ASM_AX), %r12
+ mov VCPU_R13(%_ASM_AX), %r13
+ mov VCPU_R14(%_ASM_AX), %r14
+ mov VCPU_R15(%_ASM_AX), %r15
+#endif
+
+ /* "POP" @vmcb to RAX. */
+ pop %_ASM_AX
+
+ /* Enter guest mode */
+1: vmload %_ASM_AX
+ jmp 3f
+2: cmpb $0, kvm_rebooting
+ jne 3f
+ ud2
+ _ASM_EXTABLE(1b, 2b)
+
+3: vmrun %_ASM_AX
+ jmp 5f
+4: cmpb $0, kvm_rebooting
+ jne 5f
+ ud2
+ _ASM_EXTABLE(3b, 4b)
+
+5: vmsave %_ASM_AX
+ jmp 7f
+6: cmpb $0, kvm_rebooting
+ jne 7f
+ ud2
+ _ASM_EXTABLE(5b, 6b)
+7:
+ /* "POP" @regs to RAX. */
+ pop %_ASM_AX
+
+ /* Save all guest registers. */
+ mov %_ASM_CX, VCPU_RCX(%_ASM_AX)
+ mov %_ASM_DX, VCPU_RDX(%_ASM_AX)
+ mov %_ASM_BX, VCPU_RBX(%_ASM_AX)
+ mov %_ASM_BP, VCPU_RBP(%_ASM_AX)
+ mov %_ASM_SI, VCPU_RSI(%_ASM_AX)
+ mov %_ASM_DI, VCPU_RDI(%_ASM_AX)
+#ifdef CONFIG_X86_64
+ mov %r8, VCPU_R8 (%_ASM_AX)
+ mov %r9, VCPU_R9 (%_ASM_AX)
+ mov %r10, VCPU_R10(%_ASM_AX)
+ mov %r11, VCPU_R11(%_ASM_AX)
+ mov %r12, VCPU_R12(%_ASM_AX)
+ mov %r13, VCPU_R13(%_ASM_AX)
+ mov %r14, VCPU_R14(%_ASM_AX)
+ mov %r15, VCPU_R15(%_ASM_AX)
+#endif
+
+ /*
+ * Clear all general purpose registers except RSP and RAX to prevent
+ * speculative use of the guest's values, even those that are reloaded
+ * via the stack. In theory, an L1 cache miss when restoring registers
+ * could lead to speculative execution with the guest's values.
+ * Zeroing XORs are dirt cheap, i.e. the extra paranoia is essentially
+ * free. RSP and RAX are exempt as they are restored by hardware
+ * during VM-Exit.
+ */
+ xor %ecx, %ecx
+ xor %edx, %edx
+ xor %ebx, %ebx
+ xor %ebp, %ebp
+ xor %esi, %esi
+ xor %edi, %edi
+#ifdef CONFIG_X86_64
+ xor %r8d, %r8d
+ xor %r9d, %r9d
+ xor %r10d, %r10d
+ xor %r11d, %r11d
+ xor %r12d, %r12d
+ xor %r13d, %r13d
+ xor %r14d, %r14d
+ xor %r15d, %r15d
+#endif
+
+ pop %_ASM_BX
+
+#ifdef CONFIG_X86_64
+ pop %r12
+ pop %r13
+ pop %r14
+ pop %r15
+#else
+ pop %esi
+ pop %edi
+#endif
+ pop %_ASM_BP
+ ret
+SYM_FUNC_END(__svm_vcpu_run)