Module Name: src
Committed By: maxv
Date: Wed Aug 26 16:30:50 UTC 2020
Modified Files:
src/sys/dev/nvmm/x86: nvmm_x86_vmx.c
Log Message:
nvmm-x86-vmx: improve the handling of CR4
- Filter out certain features we don't want the guest to enable. This is
for general correctness, and future-proofness.
- Flush the guest TLB when certain flags change.
To generate a diff of this commit:
cvs rdiff -u -r1.72 -r1.73 src/sys/dev/nvmm/x86/nvmm_x86_vmx.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/nvmm/x86/nvmm_x86_vmx.c
diff -u src/sys/dev/nvmm/x86/nvmm_x86_vmx.c:1.72 src/sys/dev/nvmm/x86/nvmm_x86_vmx.c:1.73
--- src/sys/dev/nvmm/x86/nvmm_x86_vmx.c:1.72 Sat Aug 22 11:01:10 2020
+++ src/sys/dev/nvmm/x86/nvmm_x86_vmx.c Wed Aug 26 16:30:50 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: nvmm_x86_vmx.c,v 1.72 2020/08/22 11:01:10 maxv Exp $ */
+/* $NetBSD: nvmm_x86_vmx.c,v 1.73 2020/08/26 16:30:50 maxv Exp $ */
/*
* Copyright (c) 2018-2020 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nvmm_x86_vmx.c,v 1.72 2020/08/22 11:01:10 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nvmm_x86_vmx.c,v 1.73 2020/08/26 16:30:50 maxv Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -729,6 +729,33 @@ static uint64_t vmx_xcr0_mask __read_mos
#define MSRBM_NPAGES 1
#define MSRBM_SIZE (MSRBM_NPAGES * PAGE_SIZE)
+#define CR4_VALID \
+ (CR4_VME | \
+ CR4_PVI | \
+ CR4_TSD | \
+ CR4_DE | \
+ CR4_PSE | \
+ CR4_PAE | \
+ CR4_MCE | \
+ CR4_PGE | \
+ CR4_PCE | \
+ CR4_OSFXSR | \
+ CR4_OSXMMEXCPT | \
+ CR4_UMIP | \
+ /* CR4_LA57 excluded */ \
+ /* CR4_VMXE excluded */ \
+ /* CR4_SMXE excluded */ \
+ CR4_FSGSBASE | \
+ CR4_PCIDE | \
+ CR4_OSXSAVE | \
+ CR4_SMEP | \
+ CR4_SMAP \
+ /* CR4_PKE excluded */ \
+ /* CR4_CET excluded */ \
+ /* CR4_PKS excluded */)
+#define CR4_INVALID \
+ (0xFFFFFFFFFFFFFFFFULL & ~CR4_VALID)
+
#define EFER_TLB_FLUSH \
(EFER_NXE|EFER_LMA|EFER_LME)
#define CR0_TLB_FLUSH \
@@ -1589,12 +1616,18 @@ vmx_inkernel_handle_cr4(struct nvmm_mach
gpr = cpudata->gprs[gpr];
}
+ if (gpr & CR4_INVALID) {
+ return -1;
+ }
cr4 = gpr | CR4_VMXE;
-
if (vmx_check_cr(cr4, vmx_cr4_fixed0, vmx_cr4_fixed1) == -1) {
return -1;
}
+ if ((vmx_vmread(VMCS_GUEST_CR4) ^ cr4) & CR4_TLB_FLUSH) {
+ cpudata->gtlb_want_flush = true;
+ }
+
vmx_vmwrite(VMCS_GUEST_CR4, cr4);
vmx_inkernel_advance();
return 0;
@@ -2514,7 +2547,7 @@ vmx_vcpu_setstate(struct nvmm_cpu *vcpu)
cpudata->gcr2 = state->crs[NVMM_X64_CR_CR2];
vmx_vmwrite(VMCS_GUEST_CR3, state->crs[NVMM_X64_CR_CR3]); // XXX PDPTE?
vmx_vmwrite(VMCS_GUEST_CR4,
- state->crs[NVMM_X64_CR_CR4] | CR4_VMXE);
+ (state->crs[NVMM_X64_CR_CR4] & CR4_VALID) | CR4_VMXE);
cpudata->gcr8 = state->crs[NVMM_X64_CR_CR8];
if (vmx_xcr0_mask != 0) {
@@ -2839,8 +2872,9 @@ vmx_vcpu_init(struct nvmm_machine *mach,
vmx_vmwrite(VMCS_CR0_MASK, CR0_NW|CR0_CD|CR0_ET);
vmx_vmwrite(VMCS_CR0_SHADOW, CR0_ET);
- /* Force CR4_VMXE to zero. */
- vmx_vmwrite(VMCS_CR4_MASK, CR4_VMXE);
+ /* Force unsupported CR4 fields to zero. */
+ vmx_vmwrite(VMCS_CR4_MASK, CR4_INVALID);
+ vmx_vmwrite(VMCS_CR4_SHADOW, 0);
/* Set the Host state for resuming. */
vmx_vmwrite(VMCS_HOST_RIP, (uint64_t)&vmx_resume_rip);
