git: a46eccfd27c3 - stable/13 - bhyve: Initialize more registers in vcpu_reset()

The branch stable/13 has been updated by corvink:

URL: https://cgit.FreeBSD.org/src/commit/?id=a46eccfd27c35affdb1e48b28e3f6ccd35001592

commit a46eccfd27c35affdb1e48b28e3f6ccd35001592
Author:     Corvin Köhne <CorvinK@beckhoff.com>
AuthorDate: 2022-07-27 14:41:02 +0000
Commit:     Corvin Köhne <corvink@FreeBSD.org>
CommitDate: 2022-12-09 13:18:03 +0000

    bhyve: Initialize more registers in vcpu_reset()
    
    - Clear CR2, EFER, and R8-15 to zero.
    - Reset DR6 and DR7 to their documented reset values.
    - Reset interrupt shadow state.
    - Document the reason CR0 is reset to a value that doesn't match its
    documented value.
    
    Reviewed by:    jhb
    Differential Revision:  https://reviews.freebsd.org/D35622
    Sponsored by:   Beckhoff Automation GmbH & Co. KG
    
    (cherry picked from commit 56b8f5b11171375bf5da484577926b53ce56a3be)
---
 lib/libvmmapi/vmmapi.c | 40 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 38 insertions(+), 2 deletions(-)

diff --git a/lib/libvmmapi/vmmapi.c b/lib/libvmmapi/vmmapi.c
index 4e4393d81961..f6d83dd0e08f 100644
--- a/lib/libvmmapi/vmmapi.c
+++ b/lib/libvmmapi/vmmapi.c
@@ -1174,13 +1174,21 @@ vcpu_reset(struct vmctx *vmctx, int vcpu)
 	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_RIP, rip)) != 0)
 		goto done;
 
+	/*
+	 * According to Intels Software Developer Manual CR0 should be
+	 * initialized with CR0_ET | CR0_NW | CR0_CD but that crashes some
+	 * guests like Windows.
+	 */
 	cr0 = CR0_NE;
 	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_CR0, cr0)) != 0)
 		goto done;
 
+	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_CR2, zero)) != 0)
+		goto done;
+
 	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_CR3, zero)) != 0)
 		goto done;
-	
+
 	cr4 = 0;
 	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_CR4, cr4)) != 0)
 		goto done;
@@ -1243,6 +1251,9 @@ vcpu_reset(struct vmctx *vmctx, int vcpu)
 	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_GS, sel)) != 0)
 		goto done;
 
+	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_EFER, zero)) != 0)
+		goto done;
+
 	/* General purpose registers */
 	rdx = 0xf00;
 	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_RAX, zero)) != 0)
@@ -1261,6 +1272,22 @@ vcpu_reset(struct vmctx *vmctx, int vcpu)
 		goto done;
 	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_RSP, zero)) != 0)
 		goto done;
+	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_R8, zero)) != 0)
+		goto done;
+	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_R9, zero)) != 0)
+		goto done;
+	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_R10, zero)) != 0)
+		goto done;
+	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_R11, zero)) != 0)
+		goto done;
+	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_R12, zero)) != 0)
+		goto done;
+	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_R13, zero)) != 0)
+		goto done;
+	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_R14, zero)) != 0)
+		goto done;
+	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_R15, zero)) != 0)
+		goto done;
 
 	/* GDTR, IDTR */
 	desc_base = 0;
@@ -1301,7 +1328,16 @@ vcpu_reset(struct vmctx *vmctx, int vcpu)
 	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_LDTR, 0)) != 0)
 		goto done;
 
-	/* XXX cr2, debug registers */
+	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_DR6,
+		 0xffff0ff0)) != 0)
+		goto done;
+	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_DR7, 0x400)) !=
+	    0)
+		goto done;
+
+	if ((error = vm_set_register(vmctx, vcpu, VM_REG_GUEST_INTR_SHADOW,
+		 zero)) != 0)
+		goto done;
 
 	error = 0;
 done: