The "unrestricted guest" capability is a feature of Intel VT-x that allows

the guest to execute real or unpaged protected mode code - bhyve relies on
this feature to execute the AP bootstrap code.

Get rid of the hack that allowed bhyve to support SMP guests on processors
that do not have the "unrestricted guest" capability. This hack was entirely
FreeBSD-specific and would not work with any other guest OS.

Instead, limit the number of vcpus to 1 when executing on processors without
"unrestricted guest" capability.

Suggested by:	grehan
Obtained from:	NetApp

1 files changed, 0 insertions, 43 deletions

diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c
index f7423be..33e0814 100644
--- a/sys/amd64/amd64/mp_machdep.c
+++ b/sys/amd64/amd64/mp_machdep.c
@@ -145,26 +145,6 @@ struct cpu_info {
 int cpu_apic_ids[MAXCPU];
 int apic_cpuids[MAX_APIC_ID + 1];
 
-/*
- * Trampoline for hypervisor direct 64-bit jump.
- *
- *   0  -	signature for guest->host verification
- *   8  -	virtual address of this page
- *  16  -	instruction virtual address
- *  24  -	stack pointer virtual address
- *  32  -	CR3, physical address of kernel page table
- *  40  -	24-byte area for null/code/data GDT entries
- */
-#define MP_V64T_SIG	0xcafebabecafebabeULL
-struct mp_v64tramp {
-	uint64_t	mt_sig;
-	uint64_t	mt_virt;
-	uint64_t	mt_eip;
-	uint64_t	mt_rsp;
-	uint64_t	mt_cr3;
-	uint64_t	mt_gdtr[3];
-};
-
 /* Holds pending bitmap based IPIs per CPU */
 static volatile u_int cpu_ipi_pending[MAXCPU];
 
@@ -967,29 +947,6 @@ start_all_aps(void)
 		bootSTK = (char *)bootstacks[cpu] + KSTACK_PAGES * PAGE_SIZE - 8;
 		bootAP = cpu;
 
-		/*
-		 * If running in a VM that doesn't support the unrestricted
-		 * guest 16-bit mode, forget most of the above and create
-		 * the data block that allows the hypervisor to direct-jump
-		 * into 64-bit mode. Copy this over the top of the 16-bit
-		 * bootstrap. The startup-IPI informs the hypervisor which
-		 * physical page this data block lies in. The hypervisor
-		 * will then use the block to initialise register state of
-		 * the AP in an almost identical fashion to how it builds
-		 * the BSP initial register state.
-		 */
-		if (testenv("hw.use_bvm_mptramp")) {
-			struct mp_v64tramp mv;
-
-			bzero(&mv, sizeof(mv));
-			mv.mt_sig = MP_V64T_SIG;
-			mv.mt_virt = (uint64_t) va;
-			mv.mt_eip = (uint64_t) init_secondary;
-			mv.mt_rsp = (uint64_t) bootSTK;
-			mv.mt_cr3 = KPML4phys;
-			bcopy(&mv, (void *) va, sizeof(mv));
-		}
-
 		/* attempt to start the Application Processor */
 		if (!start_ap(apic_id)) {
 			/* restore the warmstart vector */