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 | 7 +------
arch/x86/kernel/sev-shared.c | 25 +++++++++----------------
arch/x86/kernel/sev.c | 13 ++++++-------
3 files changed, 16 insertions(+), 29 deletions(-)
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -53,7 +53,6 @@ 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);
@@ -82,11 +81,7 @@ 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);
+
#else
static inline void sev_es_ist_enter(struct pt_regs *regs) { }
static inline void sev_es_ist_exit(void) { }
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -633,8 +633,7 @@ 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;
@@ -852,7 +851,7 @@ 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,
@@ -1102,7 +1101,7 @@ 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;
@@ -1132,7 +1131,7 @@ 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)
@@ -1141,7 +1140,7 @@ 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;
@@ -1182,7 +1181,7 @@ 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;
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -133,9 +133,10 @@ 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;
@@ -145,14 +146,7 @@ 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);
@@ -432,7 +426,7 @@ 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;
@@ -474,8 +468,7 @@ 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;
@@ -506,7 +499,7 @@ 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;
@@ -531,7 +524,7 @@ 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;