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From: Tom Lendacky <thomas.lendacky@amd.com>
To: <linux-kernel@vger.kernel.org>, <x86@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	"Kirill A. Shutemov" <kirill@shutemov.name>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Michael Roth <michael.roth@amd.com>,
	Joerg Roedel <jroedel@suse.de>, Andy Lutomirski <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH v5 4/6] x86/sev: Allow for use of the early boot GHCB for PSC requests
Date: Tue, 27 Sep 2022 12:04:19 -0500	[thread overview]
Message-ID: <1913bdc41fed623a3bea273615303a98db35cedc.1664298261.git.thomas.lendacky@amd.com> (raw)
In-Reply-To: <cover.1664298261.git.thomas.lendacky@amd.com>

Using a GHCB for a page stage change (as opposed to the MSR protocol)
allows for multiple pages to be processed in a single request. In prep
for early PSC requests in support of unaccepted memory, update the
invocation of vmgexit_psc() to be able to use the early boot GHCB and not
just the per-CPU GHCB structure.

In order to use the proper GHCB (early boot vs per-CPU), set a flag that
indicates when the per-CPU GHCBs are available and registered. For APs,
the per-CPU GHCBs are created before they are started and registered upon
startup, so this flag can be used globally for the BSP and APs instead of
creating a per-CPU flag. This will allow for a significant reduction in
the number of MSR protocol page state change requests when accepting
memory.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
 arch/x86/kernel/sev.c | 61 +++++++++++++++++++++++++++----------------
 1 file changed, 38 insertions(+), 23 deletions(-)

diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 664a4de91757..0b958d77abb4 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -117,7 +117,19 @@ static DEFINE_PER_CPU(struct sev_es_save_area *, sev_vmsa);
 
 struct sev_config {
 	__u64 debug		: 1,
-	      __reserved	: 63;
+
+	      /*
+	       * A flag used by __set_pages_state() that indicates when the
+	       * per-CPU GHCB has been created and registered and thus can be
+	       * used by the BSP instead of the early boot GHCB.
+	       *
+	       * For APs, the per-CPU GHCB is created before they are started
+	       * and registered upon startup, so this flag can be used globally
+	       * for the BSP and APs.
+	       */
+	      ghcbs_initialized	: 1,
+
+	      __reserved	: 62;
 };
 
 static struct sev_config sev_cfg __read_mostly;
@@ -660,7 +672,7 @@ static void pvalidate_pages(unsigned long vaddr, unsigned int npages, bool valid
 	}
 }
 
-static void __init early_set_pages_state(unsigned long paddr, unsigned int npages, enum psc_op op)
+static void early_set_pages_state(unsigned long paddr, unsigned int npages, enum psc_op op)
 {
 	unsigned long paddr_end;
 	u64 val;
@@ -742,26 +754,13 @@ void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op
 		WARN(1, "invalid memory op %d\n", op);
 }
 
-static int vmgexit_psc(struct snp_psc_desc *desc)
+static int vmgexit_psc(struct ghcb *ghcb, struct snp_psc_desc *desc)
 {
 	int cur_entry, end_entry, ret = 0;
 	struct snp_psc_desc *data;
-	struct ghcb_state state;
 	struct es_em_ctxt ctxt;
-	unsigned long flags;
-	struct ghcb *ghcb;
 
-	/*
-	 * __sev_get_ghcb() needs to run with IRQs disabled because it is using
-	 * a per-CPU GHCB.
-	 */
-	local_irq_save(flags);
-
-	ghcb = __sev_get_ghcb(&state);
-	if (!ghcb) {
-		ret = 1;
-		goto out_unlock;
-	}
+	vc_ghcb_invalidate(ghcb);
 
 	/* Copy the input desc into GHCB shared buffer */
 	data = (struct snp_psc_desc *)ghcb->shared_buffer;
@@ -818,20 +817,18 @@ static int vmgexit_psc(struct snp_psc_desc *desc)
 	}
 
 out:
-	__sev_put_ghcb(&state);
-
-out_unlock:
-	local_irq_restore(flags);
-
 	return ret;
 }
 
 static void __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr,
 			      unsigned long vaddr_end, int op)
 {
+	struct ghcb_state state;
 	struct psc_hdr *hdr;
 	struct psc_entry *e;
+	unsigned long flags;
 	unsigned long pfn;
+	struct ghcb *ghcb;
 	int i;
 
 	hdr = &data->hdr;
@@ -861,8 +858,20 @@ static void __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr,
 		i++;
 	}
 
-	if (vmgexit_psc(data))
+	local_irq_save(flags);
+
+	if (sev_cfg.ghcbs_initialized)
+		ghcb = __sev_get_ghcb(&state);
+	else
+		ghcb = boot_ghcb;
+
+	if (!ghcb || vmgexit_psc(ghcb, data))
 		sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
+
+	if (sev_cfg.ghcbs_initialized)
+		__sev_put_ghcb(&state);
+
+	local_irq_restore(flags);
 }
 
 static void set_pages_state(unsigned long vaddr, unsigned int npages, int op)
@@ -870,6 +879,10 @@ static void set_pages_state(unsigned long vaddr, unsigned int npages, int op)
 	unsigned long vaddr_end, next_vaddr;
 	struct snp_psc_desc desc;
 
+	/* Use the MSR protocol when a GHCB is not available. */
+	if (!boot_ghcb)
+		return early_set_pages_state(__pa(vaddr), npages, op);
+
 	vaddr = vaddr & PAGE_MASK;
 	vaddr_end = vaddr + ((unsigned long)npages << PAGE_SHIFT);
 
@@ -1248,6 +1261,8 @@ void setup_ghcb(void)
 		if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
 			snp_register_per_cpu_ghcb();
 
+		sev_cfg.ghcbs_initialized = true;
+
 		return;
 	}
 
-- 
2.37.3


  parent reply	other threads:[~2022-09-27 17:05 UTC|newest]

Thread overview: 207+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-14 12:02 [PATCHv7 00/14] mm, x86/cc: Implement support for unaccepted memory Kirill A. Shutemov
2022-06-14 12:02 ` [PATCHv7 01/14] x86/boot: Centralize __pa()/__va() definitions Kirill A. Shutemov
2022-06-23 17:37   ` Dave Hansen
2022-06-14 12:02 ` [PATCHv7 02/14] mm: Add support for unaccepted memory Kirill A. Shutemov
2022-06-14 12:57   ` Gupta, Pankaj
2022-06-17 19:28   ` Tom Lendacky
2022-06-17 20:53     ` Tom Lendacky
2022-07-21 15:14   ` Borislav Petkov
2022-07-21 15:49     ` Dave Hansen
2022-07-22 19:18       ` Borislav Petkov
2022-07-22 19:30         ` Dave Hansen
2022-07-25 12:23           ` Borislav Petkov
2022-07-25 12:38             ` David Hildenbrand
2022-07-25 12:53               ` Borislav Petkov
2022-07-26 14:30                 ` David Hildenbrand
2022-07-25 13:00             ` Mike Rapoport
2022-07-25 13:05               ` Borislav Petkov
2022-08-05 11:49   ` Vlastimil Babka
2022-08-05 12:09     ` David Hildenbrand
2022-08-05 13:38       ` Vlastimil Babka
2022-08-05 14:22         ` David Hildenbrand
2022-08-05 14:53           ` Dave Hansen
2022-08-05 14:41         ` Dave Hansen
2022-08-05 18:17           ` Vlastimil Babka
2022-08-08 15:55             ` Dave Hansen
2022-08-10 14:19     ` Mel Gorman
2022-08-15 21:08       ` Dionna Amalie Glaze
2022-08-15 22:02         ` Tom Lendacky
2022-08-29 16:02           ` Dionna Amalie Glaze
2022-08-29 16:19             ` Dave Hansen
2022-09-06 17:50               ` Dionna Amalie Glaze
2022-09-08 12:11                 ` Mike Rapoport
2022-09-08 16:23                   ` Dionna Amalie Glaze
2022-09-08 19:28                     ` Mike Rapoport
2022-09-22 14:31                       ` Tom Lendacky
2022-09-24  1:03                         ` Kirill A. Shutemov
2022-09-24  9:36                           ` Mike Rapoport
2022-09-26 12:10                           ` Kirill A. Shutemov
2022-09-26 13:38                             ` Tom Lendacky
2022-09-26 15:42                               ` Kirill A. Shutemov
2022-09-26 15:42                               ` Tom Lendacky
2022-06-14 12:02 ` [PATCHv7 03/14] mm: Report unaccepted memory in meminfo Kirill A. Shutemov
2022-07-26 14:33   ` David Hildenbrand
2022-06-14 12:02 ` [PATCHv7 04/14] efi/x86: Get full memory map in allocate_e820() Kirill A. Shutemov
2022-07-25 13:02   ` Borislav Petkov
2022-06-14 12:02 ` [PATCHv7 05/14] x86/boot: Add infrastructure required for unaccepted memory support Kirill A. Shutemov
2022-06-15 10:19   ` Peter Zijlstra
2022-06-15 15:05     ` Kirill A. Shutemov
2022-07-17 17:16       ` Borislav Petkov
2022-07-25 21:33   ` Borislav Petkov
2022-06-14 12:02 ` [PATCHv7 06/14] efi/x86: Implement support for unaccepted memory Kirill A. Shutemov
2022-06-22 19:58   ` Dave Hansen
2022-07-26  8:35   ` Borislav Petkov
2022-06-14 12:02 ` [PATCHv7 07/14] x86/boot/compressed: Handle " Kirill A. Shutemov
2022-06-14 12:02 ` [PATCHv7 08/14] x86/mm: Reserve unaccepted memory bitmap Kirill A. Shutemov
2022-07-26  9:07   ` Borislav Petkov
2022-11-30  1:28     ` Kirill A. Shutemov
2022-12-01  9:37       ` Mike Rapoport
2022-12-01 13:47         ` Kirill A. Shutemov
2022-06-14 12:02 ` [PATCHv7 09/14] x86/mm: Provide helpers for unaccepted memory Kirill A. Shutemov
2022-06-14 12:02 ` [PATCHv7 10/14] x86/mm: Avoid load_unaligned_zeropad() stepping into " Kirill A. Shutemov
2022-06-23 17:19   ` Dave Hansen
2022-07-26 10:21   ` Borislav Petkov
2022-08-02 23:46     ` Dave Hansen
2022-08-03 14:02       ` Dave Hansen
2022-08-11 11:26         ` Borislav Petkov
2022-08-13 16:11           ` Andy Lutomirski
2022-08-13 21:13             ` Kirill A. Shutemov
2022-08-13 16:04         ` Andy Lutomirski
2022-08-13 20:58           ` Kirill A. Shutemov
2022-07-26 17:25   ` Borislav Petkov
2022-07-26 17:46     ` Dave Hansen
2022-07-26 20:17   ` Andy Lutomirski
2022-08-09 11:38     ` Kirill A. Shutemov
2022-08-13 16:03       ` Andy Lutomirski
2022-08-13 21:02         ` Kirill A. Shutemov
2022-06-14 12:02 ` [PATCHv7 11/14] x86: Disable kexec if system has " Kirill A. Shutemov
2022-06-23 17:23   ` Dave Hansen
2022-06-23 17:23     ` Dave Hansen
2022-06-23 21:48     ` Eric W. Biederman
2022-06-23 21:48       ` Eric W. Biederman
2022-06-24  2:00       ` Kirill A. Shutemov
2022-06-24  2:00         ` Kirill A. Shutemov
2022-06-28 23:51         ` Kirill A. Shutemov
2022-06-28 23:51           ` Kirill A. Shutemov
2022-06-29  0:10           ` Dave Hansen
2022-06-29  0:10             ` Dave Hansen
2022-06-29  0:59             ` Kirill A. Shutemov
2022-06-29  0:59               ` Kirill A. Shutemov
2022-07-04  7:18               ` Dave Young
2022-07-04  7:18                 ` Dave Young
2022-06-14 12:02 ` [PATCHv7 12/14] x86/tdx: Make _tdx_hypercall() and __tdx_module_call() available in boot stub Kirill A. Shutemov
2022-06-23 17:25   ` Dave Hansen
2022-06-14 12:02 ` [PATCHv7 13/14] x86/tdx: Refactor try_accept_one() Kirill A. Shutemov
2022-06-23 17:31   ` Dave Hansen
2022-07-26 10:58   ` Borislav Petkov
2022-06-14 12:02 ` [PATCHv7 14/14] x86/tdx: Add unaccepted memory support Kirill A. Shutemov
2022-06-24 16:22   ` Dave Hansen
2022-06-27 10:42     ` Kirill A. Shutemov
2022-07-26 14:51   ` Borislav Petkov
2022-08-09 11:45     ` Kirill A. Shutemov
2022-08-10 10:27       ` Borislav Petkov
2022-06-24 16:37 ` [PATCHv7 00/14] mm, x86/cc: Implement support for unaccepted memory Peter Gonda
2022-06-24 16:57   ` Dave Hansen
2022-06-24 17:06     ` Marc Orr
2022-06-24 17:09       ` Dave Hansen
2022-06-24 17:15         ` Peter Gonda
2022-06-24 17:19         ` Marc Orr
2022-06-24 17:21           ` Peter Gonda
2022-06-24 17:47           ` Dave Hansen
2022-06-24 18:10             ` Peter Gonda
2022-06-24 18:13               ` Dave Hansen
2022-06-24 17:40   ` Michael Roth
2022-06-24 17:58     ` Michael Roth
2022-06-24 18:05     ` Peter Gonda
2022-06-27 11:30   ` Kirill A. Shutemov
2022-06-27 11:54     ` Ard Biesheuvel
2022-06-27 12:22       ` Kirill A. Shutemov
2022-06-27 16:17         ` Peter Gonda
2022-06-27 16:33           ` Ard Biesheuvel
2022-06-27 22:38             ` Kirill A. Shutemov
2022-06-28 17:17               ` Ard Biesheuvel
2022-07-18 17:21                 ` Kirill A. Shutemov
2022-07-18 23:32                   ` Dionna Amalie Glaze
2022-07-19  0:31                     ` Dionna Amalie Glaze
2022-07-19 18:29                       ` Dionna Amalie Glaze
2022-07-19 19:13                         ` Borislav Petkov
2022-07-19 20:45                           ` Ard Biesheuvel
2022-07-19 21:23                             ` Borislav Petkov
2022-07-19 21:35                               ` Dave Hansen
2022-07-19 21:50                                 ` Borislav Petkov
2022-07-19 22:01                                   ` Kirill A. Shutemov
2022-07-19 22:02                                   ` Dave Hansen
2022-07-19 22:08                                     ` Tom Lendacky
2022-07-20  0:26                                     ` Marc Orr
2022-07-20  5:44                                       ` Borislav Petkov
2022-07-20 17:03                                         ` Marc Orr
2022-07-22 15:07                                           ` Borislav Petkov
2022-07-21 17:12                                       ` Dave Hansen
2022-07-23 11:14                                         ` Ard Biesheuvel
2022-07-28 22:01                                           ` Dionna Amalie Glaze
2022-08-09 11:14                                           ` Kirill A. Shutemov
2022-08-09 11:36                                             ` Ard Biesheuvel
2022-08-09 11:54                                               ` Kirill A. Shutemov
2022-08-09 21:09                                                 ` Dionna Amalie Glaze
2022-07-19  2:48                     ` Yao, Jiewen
2022-07-29 14:01 ` [PATCH v1 0/2] Provide SEV-SNP " Tom Lendacky
2022-07-29 14:01   ` [PATCH v1 1/2] x86/sev: Use per-CPU PSC structure in prep for unaccepted memory support Tom Lendacky
2022-07-29 14:18     ` Dave Hansen
2022-07-29 14:25       ` Tom Lendacky
2022-07-29 19:08         ` Dave Hansen
2022-07-29 19:22           ` Tom Lendacky
2022-07-29 19:28             ` Dave Hansen
2022-07-29 20:12               ` Tom Lendacky
2022-08-03 18:11                 ` [PATCH v1.1 0/2] Provide SEV-SNP support for unaccepted memory Tom Lendacky
2022-08-03 18:11                   ` [PATCH v1.1 1/2] x86/sev: Use per-CPU PSC structure in prep for unaccepted memory support Tom Lendacky
2022-08-03 18:17                     ` Dave Hansen
2022-08-03 18:21                       ` Tom Lendacky
2022-08-03 18:24                         ` Dave Hansen
2022-08-03 21:03                           ` Tom Lendacky
2022-08-03 21:18                             ` Dave Hansen
2022-08-03 21:34                               ` Tom Lendacky
2022-08-03 21:48                                 ` Dave Hansen
2022-08-03 22:17                                   ` Tom Lendacky
2022-08-03 18:18                     ` Tom Lendacky
2022-08-03 18:11                   ` [PATCH v1.1 2/2] x86/sev: Add SNP-specific " Tom Lendacky
2022-07-29 14:01   ` [PATCH v1 " Tom Lendacky
2022-08-23  0:24     ` Dionna Amalie Glaze
2022-08-23 14:28       ` Tom Lendacky
2022-08-23 23:28     ` Dionna Amalie Glaze
2022-08-08 17:16 ` [PATCH v2 0/2] Provide SEV-SNP support for unaccepted memory Tom Lendacky
2022-08-08 17:16   ` [PATCH v2 1/2] x86/sev: Put PSC struct on the stack in prep for unaccepted memory support Tom Lendacky
2022-08-08 21:43     ` Dave Hansen
2022-08-08 22:18       ` Tom Lendacky
2022-08-08 22:33         ` Dave Hansen
2022-08-08 22:35           ` Tom Lendacky
2022-08-12 13:03     ` Borislav Petkov
2022-08-12 14:11       ` Tom Lendacky
2022-08-12 14:33         ` Borislav Petkov
2022-08-12 14:51           ` Tom Lendacky
2022-08-13 19:40             ` Borislav Petkov
2022-08-14 13:36               ` Tom Lendacky
2022-08-08 17:16   ` [PATCH v2 2/2] x86/sev: Add SNP-specific " Tom Lendacky
2022-08-15 15:57 ` [PATCH v3 0/2] Provide SEV-SNP support for unaccepted memory Tom Lendacky
2022-08-15 15:57   ` [PATCH v3 1/2] x86/sev: Put PSC struct on the stack in prep for unaccepted memory support Tom Lendacky
2022-08-17 16:08     ` Borislav Petkov
2022-08-17 21:17       ` Tom Lendacky
2022-08-15 15:57   ` [PATCH v3 2/2] x86/sev: Add SNP-specific " Tom Lendacky
2022-08-18 13:39     ` Borislav Petkov
2022-08-25 14:23 ` [PATCH v4 0/4] Provide SEV-SNP support for unaccepted memory Tom Lendacky
2022-08-25 14:23   ` [PATCH v4 1/4] x86/sev: Put PSC struct on the stack in prep for unaccepted memory support Tom Lendacky
2022-09-20 16:15     ` Borislav Petkov
2022-08-25 14:23   ` [PATCH v4 2/4] x86/sev: Allow for use of the early boot GHCB for PSC requests Tom Lendacky
2022-08-25 14:23   ` [PATCH v4 3/4] x86/sev: Use large PSC requests if applicable Tom Lendacky
2022-08-25 14:23   ` [PATCH v4 4/4] x86/sev: Add SNP-specific unaccepted memory support Tom Lendacky
2022-08-25 22:10     ` Dionna Amalie Glaze
2022-08-26 21:29       ` Tom Lendacky
2022-09-27 17:04 ` [PATCH v5 0/6] Provide SEV-SNP support for unaccepted memory Tom Lendacky
2022-09-27 17:04   ` [PATCH v5 1/6] x86/sev: Fix calculation of end address based on number of pages Tom Lendacky
2022-09-27 17:10     ` Dave Hansen
2022-09-27 20:45       ` Tom Lendacky
2022-09-27 19:04     ` Dionna Amalie Glaze
2022-09-27 17:04   ` [PATCH v5 2/6] " Tom Lendacky
2022-09-27 17:04   ` [PATCH v5 3/6] x86/sev: Put PSC struct on the stack in prep for unaccepted memory support Tom Lendacky
2022-09-27 17:04   ` Tom Lendacky [this message]
2022-09-27 17:04   ` [PATCH v5 5/6] x86/sev: Use large PSC requests if applicable Tom Lendacky
2022-09-27 17:04   ` [PATCH v5 6/6] x86/sev: Add SNP-specific unaccepted memory support Tom Lendacky

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