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From: Borislav Petkov <bp@suse.de>
Date: Wed, 27 Jul 2022 13:24:21 +0200
Subject: Revert "x86/sev: Expose sev_es_ghcb_hv_call() for use by HyperV"
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Git-commit: 5bb6c1d1126ebcbcd6314f80d82f50b021a9e351
Patch-mainline: v5.19
References: bsc#1190497

This reverts commit 007faec014cb5d26983c1f86fd08c6539b41392e.

Now that hyperv does its own protocol negotiation:

  49d6a3c062a1 ("x86/Hyper-V: Add SEV negotiate protocol support in Isolation VM")

revert this exposure of the sev_es_ghcb_hv_call() helper.

Cc: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by:Tianyu Lan <tiala@microsoft.com>
Link: https://lore.kernel.org/r/20220614014553.1915929-1-ltykernel@gmail.com
---
 arch/x86/include/asm/sev.h   |    6 ------
 arch/x86/kernel/sev-shared.c |   25 +++++++++----------------
 arch/x86/kernel/sev.c        |   17 ++++++++---------
 3 files changed, 17 insertions(+), 31 deletions(-)

--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -72,7 +72,6 @@ static inline u64 lower_bits(u64 val, un
 
 struct real_mode_header;
 enum stack_type;
-struct ghcb;
 
 /* Early IDT entry points for #VC handler */
 extern void vc_no_ghcb(void);
@@ -117,11 +116,6 @@ static __always_inline void sev_es_nmi_c
 		__sev_es_nmi_complete();
 }
 extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
-extern enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
-					  bool set_ghcb_msr,
-					  struct es_em_ctxt *ctxt,
-					  u64 exit_code, u64 exit_info_1,
-					  u64 exit_info_2);
 static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs)
 {
 	int rc;
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -222,9 +222,10 @@ static enum es_result verify_exception_i
 	return ES_VMM_ERROR;
 }
 
-enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr,
-				   struct es_em_ctxt *ctxt, u64 exit_code,
-				   u64 exit_info_1, u64 exit_info_2)
+static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
+					  struct es_em_ctxt *ctxt,
+					  u64 exit_code, u64 exit_info_1,
+					  u64 exit_info_2)
 {
 	/* Fill in protocol and format specifiers */
 	ghcb->protocol_version = ghcb_version;
@@ -234,14 +235,7 @@ enum es_result sev_es_ghcb_hv_call(struc
 	ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
 	ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
 
-	/*
-	 * Hyper-V unenlightened guests use a paravisor for communicating and
-	 * GHCB pages are being allocated and set up by that paravisor. Linux
-	 * should not change the GHCB page's physical address.
-	 */
-	if (set_ghcb_msr)
-		sev_es_wr_ghcb_msr(__pa(ghcb));
-
+	sev_es_wr_ghcb_msr(__pa(ghcb));
 	VMGEXIT();
 
 	return verify_exception_info(ghcb, ctxt);
@@ -798,7 +792,7 @@ static enum es_result vc_handle_ioio(str
 		 */
 		sw_scratch = __pa(ghcb) + offsetof(struct ghcb, shared_buffer);
 		ghcb_set_sw_scratch(ghcb, sw_scratch);
-		ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_IOIO,
+		ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO,
 					  exit_info_1, exit_info_2);
 		if (ret != ES_OK)
 			return ret;
@@ -840,8 +834,7 @@ static enum es_result vc_handle_ioio(str
 
 		ghcb_set_rax(ghcb, rax);
 
-		ret = sev_es_ghcb_hv_call(ghcb, true, ctxt,
-					  SVM_EXIT_IOIO, exit_info_1, 0);
+		ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO, exit_info_1, 0);
 		if (ret != ES_OK)
 			return ret;
 
@@ -897,7 +890,7 @@ static enum es_result vc_handle_cpuid(st
 		/* xgetbv will cause #GP - use reset value for xcr0 */
 		ghcb_set_xcr0(ghcb, 1);
 
-	ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_CPUID, 0, 0);
+	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_CPUID, 0, 0);
 	if (ret != ES_OK)
 		return ret;
 
@@ -922,7 +915,7 @@ static enum es_result vc_handle_rdtsc(st
 	bool rdtscp = (exit_code == SVM_EXIT_RDTSCP);
 	enum es_result ret;
 
-	ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, exit_code, 0, 0);
+	ret = sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, 0, 0);
 	if (ret != ES_OK)
 		return ret;
 
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -728,7 +728,7 @@ static int vmgexit_psc(struct snp_psc_de
 		ghcb_set_sw_scratch(ghcb, (u64)__pa(data));
 
 		/* This will advance the shared buffer data points to. */
-		ret = sev_es_ghcb_hv_call(ghcb, true, &ctxt, SVM_VMGEXIT_PSC, 0, 0);
+		ret = sev_es_ghcb_hv_call(ghcb, &ctxt, SVM_VMGEXIT_PSC, 0, 0);
 
 		/*
 		 * Page State Change VMGEXIT can pass error code through
@@ -1154,8 +1154,7 @@ static enum es_result vc_handle_msr(stru
 		ghcb_set_rdx(ghcb, regs->dx);
 	}
 
-	ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_MSR,
-				  exit_info_1, 0);
+	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, exit_info_1, 0);
 
 	if ((ret == ES_OK) && (!exit_info_1)) {
 		regs->ax = ghcb->save.rax;
@@ -1410,7 +1409,7 @@ static enum es_result vc_do_mmio(struct
 
 	ghcb_set_sw_scratch(ghcb, ghcb_pa + offsetof(struct ghcb, shared_buffer));
 
-	return sev_es_ghcb_hv_call(ghcb, true, ctxt, exit_code, exit_info_1, exit_info_2);
+	return sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, exit_info_1, exit_info_2);
 }
 
 static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb,
@@ -1660,7 +1659,7 @@ static enum es_result vc_handle_dr7_writ
 
 	/* Using a value of 0 for ExitInfo1 means RAX holds the value */
 	ghcb_set_rax(ghcb, val);
-	ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
+	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
 	if (ret != ES_OK)
 		return ret;
 
@@ -1690,7 +1689,7 @@ static enum es_result vc_handle_dr7_read
 static enum es_result vc_handle_wbinvd(struct ghcb *ghcb,
 				       struct es_em_ctxt *ctxt)
 {
-	return sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_WBINVD, 0, 0);
+	return sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WBINVD, 0, 0);
 }
 
 static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
@@ -1699,7 +1698,7 @@ static enum es_result vc_handle_rdpmc(st
 
 	ghcb_set_rcx(ghcb, ctxt->regs->cx);
 
-	ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_RDPMC, 0, 0);
+	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_RDPMC, 0, 0);
 	if (ret != ES_OK)
 		return ret;
 
@@ -1740,7 +1739,7 @@ static enum es_result vc_handle_vmmcall(
 	if (x86_platform.hyper.sev_es_hcall_prepare)
 		x86_platform.hyper.sev_es_hcall_prepare(ghcb, ctxt->regs);
 
-	ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_VMMCALL, 0, 0);
+	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_VMMCALL, 0, 0);
 	if (ret != ES_OK)
 		return ret;
 
@@ -2230,7 +2229,7 @@ int snp_issue_guest_request(u64 exit_cod
 		ghcb_set_rbx(ghcb, input->data_npages);
 	}
 
-	ret = sev_es_ghcb_hv_call(ghcb, true, &ctxt, exit_code, input->req_gpa, input->resp_gpa);
+	ret = sev_es_ghcb_hv_call(ghcb, &ctxt, exit_code, input->req_gpa, input->resp_gpa);
 	if (ret)
 		goto e_put;